Techniques for spatially resolving received light-based communication signals

ABSTRACT

Techniques are disclosed for spatially resolving received light-based communication (LCom) signals. In an example case where one or more LCom signals are in the field of view (FOV) of an LCom receiver, the image representing the FOV may be captured and segmented into non-overlapping cells, such as hexagonal, triangular, rectangular, or circular shaped cells. Each LCom signal may be interpreted as a unique pixel cluster comprising one or more of the cells. In some cases, the LCom signals in the FOV may be received from multiple LCom-enabled luminaires and/or a single LCom-enabled luminaire having multiple light panels. The benefits of being able to spatially resolve received LCom signals may include establishing a link with multiple LCom signals within the FOV of a receiver without conflict and/or determining the location of those LCom signals, improving signal to noise ratio, augmenting position information, enhancing sampling frequency, and improving communication speed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of: U.S. Provisional PatentApplication No. 61/970,305, titled “Light Communication Protocol,” filedon Mar. 25, 2014; U.S. Provisional Patent Application No. 61/970,307,titled “Light Communication Orientation,” filed on Mar. 25, 2014; U.S.Provisional Patent Application No. 61/970,310, titled “LightCommunication Receiver,” filed on Mar. 25, 2014; U.S. Provisional PatentApplication No. 61/970,321, titled “Light Communication LuminairePositioning,” filed on Mar. 25, 2014; and U.S. Provisional PatentApplication No. 61/970,325, titled “Light Communication Navigation,”filed on Mar. 25, 2014. Each of these patent applications is hereinincorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to solid-state lighting (SSL) and moreparticularly to light-based communication via SSL.

BACKGROUND

Global positioning system (GPS) devices are commonly used to facilitatenavigation on Earth. These GPS devices are designed to communicate withorbiting satellites that transmit location and time information. Closerto the Earth's surface, such satellite-based navigation can besupplemented using local area wireless technologies, such as Wi-Fi,which utilize radio frequency (RF) signals to communicate with nearbycompatible devices. These types of wireless technologies typicallyemploy wireless access points (Wi-Fi hotspots) to establish networkaccess, and in cases of secured wireless networks, a password or othersecurity credentials normally must be provided in order to gain networkaccess.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example light-basedcommunication (LCom) system configured in accordance with an embodimentof the present disclosure.

FIG. 2A is a block diagram illustrating an LCom-enabled luminaireconfigured in accordance with an embodiment of the present disclosure.

FIG. 2B is a block diagram illustrating an LCom-enabled luminaireconfigured in accordance with another embodiment of the presentdisclosure.

FIG. 3 illustrates an example arbitrary LCom signal as may betransmitted by an LCom-enabled luminaire, in accordance with anembodiment of the present disclosure.

FIG. 4 illustrates an example computing device configured in accordancewith an embodiment of the present disclosure.

FIG. 5A is a flow diagram illustrating an example process of coding LComdata via a rolling shutter coding scheme, in accordance with anembodiment of the present disclosure.

FIG. 5B illustrates an example rolling shutter image capture via afront-facing image capture device in accordance with an embodiment ofthe present disclosure.

FIG. 5C is a flow diagram illustrating an example process of coding LComdata via an undersampling/aliasing scheme, in accordance with anembodiment of the present disclosure.

FIG. 5D illustrates an example modulation signal of fixed modulationfrequency, in accordance with an embodiment of the present disclosure.

FIG. 6A is a graph illustrating light level as a function of time for anexample case of adaptive modulation depth, in accordance with anembodiment of the present disclosure.

FIG. 6B is a block diagram illustrating a control loop of anLCom-enabled luminaire configured in accordance with an embodiment ofthe present disclosure.

FIG. 6C is a flow diagram illustrating a process of dynamicallyadjusting the modulation depth of an LCom signal, in accordance with anembodiment of the present disclosure.

FIG. 7A illustrates an example LCom system, including an LCom-enabledluminaire and a computing device, in accordance with an embodiment ofthe present disclosure.

FIG. 7B illustrates an example method for emitting position informationfrom an LCom-enabled luminaire, in accordance with an embodiment of thepresent disclosure.

FIG. 8A is a flow diagram illustrating a method of receiving LCom dataoptionally utilizing multiple light-sensing devices of a computingdevice, in accordance with an embodiment of the present disclosure.

FIG. 8B is a flow diagram illustrating a method of receiving LCom dataoptionally utilizing multiple light-sensing devices of a computingdevice, in accordance with another embodiment of the present disclosure.

FIGS. 8C and 8D are two example image frames of magnified pixel outputof a front-facing image capture device receiving light input from twoseparate transmitting LCom-enabled luminaires, in accordance with anembodiment of the present disclosure.

FIG. 8E is a graph of power ratio as a function of frequencyillustrating an example output signal of an ambient light sensorreceiving LCom signal input from two separate transmitting LCom-enabledluminaires, in accordance with an embodiment of the present disclosure.

FIG. 9A is a flow diagram illustrating a method of providing instructionto achieve proper alignment of an image capture device relative to atransmitting LCom-enabled luminaire, in accordance with an embodiment ofthe present disclosure.

FIG. 9B illustrates an example scenario of improper alignment betweenthe raster direction of a front-facing image capture device of acomputing device and a dual arrangement of paired transmittingLCom-enabled luminaires, in accordance with an embodiment of the presentdisclosure.

FIG. 9C illustrates an example scenario of proper alignment between theraster direction of a front-facing image capture device of a computingdevice and a dual arrangement of paired transmitting LCom-enabledluminaires, in accordance with an embodiment of the present disclosure.

FIG. 9D illustrates an example scenario in which a computing device isconfigured to output instruction by way of visual feedback to a user, inaccordance with an embodiment of the present disclosure.

FIG. 10A illustrates an example LCom system, including an LCom-enabledluminaire and an LCom receiver, in accordance with an embodiment of thepresent disclosure.

FIG. 10B illustrates an example method of determining an LCom receiverposition, in accordance with an embodiment of the present disclosure.

FIG. 11A illustrates an example LCom system, including an LCom-enabledluminaire and an LCom receiver, in accordance with an embodiment of thepresent disclosure.

FIG. 11B illustrates an example method of augmenting LCom receiverpositioning using an inertial navigation system (INS), in accordancewith an embodiment of the present disclosure.

FIG. 12 illustrates an example arrangement of LCom-enabled luminairesconfigured to communicate via LCom with a computing device, inaccordance with an embodiment of the present disclosure.

FIG. 13A illustrates a store including example multiple panelluminaires, in accordance with an embodiment of the present disclosure.

FIG. 13B illustrates a bottom view of an example multiple panelluminaire, in accordance with an embodiment of the present disclosure.

FIG. 13C illustrates a receiver viewing the multiple panel luminaire ofFIG. 13B from two different orientations, in accordance with anembodiment of the present disclosure.

FIG. 13D illustrates an example multiple panel luminaire transmission,in accordance with an embodiment of the present disclosure.

FIG. 14A illustrates an example field of view of an image capture deviceand a corresponding image, in accordance with an embodiment of thepresent disclosure.

FIG. 14B illustrates an example method of spatially resolving receivedLCom signals, in accordance with an embodiment of the presentdisclosure.

FIG. 14C illustrates an example field of view of an image capture deviceand a corresponding image, in accordance with another embodiment of thepresent disclosure.

These and other features of the present embodiments will be understoodbetter by reading the following detailed description, taken togetherwith the figures herein described. The accompanying drawings are notintended to be drawn to scale. In the drawings, each identical or nearlyidentical component that is illustrated in various figures may berepresented by a like numeral. For purposes of clarity, not everycomponent may be labeled in every drawing.

DETAILED DESCRIPTION

General Overview

Existing smartphones and mobile computing devices utilize a combinationof global positioning system (GPS) and Wi-Fi technologies to providenavigation capabilities, such as various Wi-Fi positioning systems(WPS). However, these existing GPS-based and Wi-Fi-based techniquessuffer from a number of limitations that make their use impractical forindoor navigation. In particular, GPS has an accuracy of only severalmeters, and the availability and range of Wi-Fi network connections arelimited by factors such as the placement of Wi-Fi hotspots, securityrestrictions imposed by network providers, and other environmentalfactors. Thus, the combination of GPS and Wi-Fi can fail to achievesufficiently refined accuracies for purposes of indoor navigation. Thisis particularly evident in the example context of attempting to navigatea user to an item of interest on a shelf in a retail store. Thesecomplications can be compounded by the fact that retail stores aretypically hesitant to grant customers access to in-store wirelessnetworks because of potential security risks.

Thus, and in accordance with some embodiments of the present disclosure,techniques are disclosed that can be implemented, for example, as asystem for navigation and positioning using light-based communication.As used herein, light-based communication (LCom) generally refers tocommunication between a solid-state luminaire and a receiver device,such as a smartphone or other mobile computing device, using a pulsinglight signal that is encoded with data. In general, the light utilizedin LCom may be of any spectral band, visible or otherwise, and may be ofany intensity, as desired for a given target application or end-use. Inaccordance with some embodiments, in an LCom system, a givenLCom-enabled luminaire may be configured to transmit a pulsing lightsignal encoded with data (an LCom signal), and a given receiver device,such as a smartphone or other mobile computing device, may be configuredto detect the pulsing light signal encoded with data via one or morelight-sensing devices, such as a camera and/or an ambient light sensor,among others.

As will be appreciated in light of this disclosure, there are manynon-trivial challenges to establishing and maintaining successful LCombetween an LCom-enabled luminaire and a given receiver device, as wellas to using LCom to determine location and positioning of the receiverdevice (and thus the user, if present) for purposes of providingnavigation, indoor or otherwise. One such challenge pertains todetermining the location of the receiver device relative to atransmitting LCom-enabled luminaire. While the LCom-enabled luminairemay be programmed to know its location in space, that information may beonly partially helpful to determining the location of a receiver device,which can be a given distance away from the LCom-enabled luminaire.Another non-trivial challenge pertains to implementing LCom-basedpositioning and navigation utilizing preexisting infrastructure andhardware, such as cameras and other sensors typically found in existingsmartphones and other mobile computing devices. A further non-trivialchallenge pertains to pulsing the light output of LCom-enabledluminaires in a manner that is detectable by the receiver device andensures that ambient light levels are kept constant while minimizingpulsing transitions so as to have only minimal or otherwise negligibleimpact on light quality and thus not be perceivable to bystanders. Yetanother non-trivial challenge pertains to transmitting LCom data in areasonably brief period of time. In general, a given user may be willingto wait for only a few seconds to gather positioning data via LCom forpurposes of indoor navigation. Thus, it may be desirable for theLCom-enabled luminaire to transmit all desired LCom data packets to thereceiver device within some optimal, user-configurable, or otherdesignated time window. Still another non-trivial challenge pertains totransmitting LCom data from an LCom-enabled luminaire to a receiverdevice in an efficient, accurate, and reliable manner. Interruptions inLCom can be caused, for example, by misalignment and movement of thereceiver device with respect to the transmitting LCom-enabled luminaire,and an LCom link may be susceptible to breakage, for example, in casesin which the receiver device moves abruptly or continuously (e.g., asmay occur when a user is moving around with the receiver device inhand). Accordingly, it may be desirable to minimize or otherwise reduceinterruptions in LCom and to correct for faulty LCom data, when present.Another non-trivial challenge pertains to handling multiple LCom signalsbeing simultaneously transmitted within the field of view (FOV) of thereceiver device in a manner that minimizes or otherwise reduces datapacket collision and channel crosstalk.

As such, some embodiments relate to coding LCom data in a manner thatallows for detection thereof, for example, via a standard low-speedsmartphone camera. In some cases, the disclosed techniques can be used,for example, in encoding and decoding LCom data in a manner that: (1)prevents or otherwise minimizes perceivable flicker of the light outputby a transmitting LCom-enabled luminaire; and/or (2) avoids or otherwisereduces a need for additional, specialized receiver hardware at thereceiver computing device. In some cases, the disclosed techniques canbe used, for example, to enhance the baud rate between a transmittingLCom-enabled luminaire and a receiver device.

Some embodiments relate to dynamically adjusting light modulation depthbased, at least in part, on ambient light levels. Under the disclosedadaptive light modulation scheme, a given LCom-enabled luminaire may beconfigured to adjust the modulation depth dynamically and/or control thesignal-to-noise ratio (SNR) such that the average light signal is keptconstant, regardless of what LCom data is being transmitted. In somecases, the disclosed techniques can be used, for example, to dynamicallyadjust light modulation depth according to a given minimum lightmodulation depth assessed by measuring the ambient lighting conditionsof the environment of the LCom-enabled luminaire. In some instances, anoptimized or other target SNR can be provided using the disclosedtechniques.

Some embodiments relate to techniques for emitting position informationfrom LCom-enabled luminaires. Luminaire position information may beemitted via an LCom signal that comprises data including the positioninformation. The data may include relative and/or absolute positioninformation for the luminaire and may indicate the physical location ofthe luminaire. Relative position information for the luminaire mayinclude coordinates relative to a point of origin or physical locationwithin the environment. Absolute position information for the luminairemay include global coordinates for the luminaire. In some cases, theabsolute position information for a luminaire may be calculated usingposition information for the luminaire relative to a point of origin orphysical location and the absolute position of the point of origin orphysical location. In some embodiments, the data may also include anenvironment identifier. An environment identifier may indicate thespecific entity or type of entity where the luminaire is located, suchas a building, train, aircraft, or ship. An environment identifier mayalso indicate to an LCom receiver which map(s) to use for theinterpretation of position information for the luminaire. As will beapparent in light of this disclosure, the techniques for emittingposition information from an LCom-enabled luminaire can be used for bothstationary and mobile luminaires. In the case of a mobile luminaire,such as a luminaire located in a moving environment (e.g., a train,aircraft, ship, elevator, etc.), the dynamic position information may beupdated in real time. For example, in the case of a luminaire in anelevator, the floor position of the luminaire may be updatedautomatically as it moves between floors.

Some embodiments relate to determining how and when to utilize a givenlight-sensitive device, such as a camera or an ambient light sensor, ofa receiver device for purposes of detecting and decoding the pulsinglight of LCom signals transmitted by an LCom-enabled luminaire. Inaccordance with some embodiments, determination of whether to utilizeonly a camera, only an ambient light sensor, or a combination thereof ingathering LCom data may be based, in part or in whole, on factorsincluding time, location, and/or context.

Some embodiments relate to providing proper raster line alignment of acamera or other light-sensing device of the receiver device relative toa transmitting LCom-enabled luminaire to establish reliable LCom therebetween. In some cases, proper alignment can be provided automatically(e.g., by the receiver device and/or other suitable controller). In somecases, proper alignment can be provided by the user. In some instancesin which a user is to be involved in the alignment process, the receiverdevice may be configured to instruct or otherwise guide the user in theprocess of properly aligning the receiver device relative to a giventransmitting LCom-enabled luminaire.

Some embodiments relate to techniques for determining an LCom receiverposition. In some such embodiments, the techniques can be used todetermine the position of a receiver relative to a specific luminairewithin the FOV of the receiver camera. For example, the relativeposition may be calculated by determining the distance and theorientation of the receiver relative to the luminaire. The distancerelative to the luminaire can be calculated using the observed size ofthe luminaire in an image generated by the receiver camera, the imagezoom factor, and actual geometry of the luminaire. The luminairegeometry, such as the length or width of the luminaire, may be receivedvia an LCom signal transmitted from the luminaire or the receiver mayretrieve the dimensions in another suitable manner (e.g., via a lookuptable). The orientation relative to the luminaire may be determinedusing a fiducial associated with the luminaire, the fiducial beingdetectable within the image generated by the camera. An example fiducialmay include a special marking on the luminaire, a non-symmetricluminaire design aspect, a unique geometry of the luminaire, or someother aspect of the luminaire recognizable by the receiver camera to beused as an orientation cue. The orientation may also be determined usingthe yaw, pitch, and roll of the receiver and/or the luminaire. Inaddition, the orientation may be determined using the absolute headingof the receiver. Once the position of a receiver relative to a luminairewithin the FOV of the receiver is determined, the absolute position ofthe receiver may be calculated using the absolute position of theluminaire. The absolute position of the luminaire may be determinedbased on an LCom signal received from the luminaire or in anothersuitable manner, such as via a lookup table using the ID of theluminaire.

Some embodiments relate to techniques for augmenting LCom receiverpositioning using, for example, an inertial navigation system (INS). AnLCom receiver INS may utilize an on-board accelerometer(s) and/orgyroscopic sensor to calculate, via dead reckoning, the position,orientation, and velocity of the receiver. In this manner, the LComreceiver can calculate its relative position using the INS based on aknown starting point. As variously described herein, an LCom receivermay primarily rely on determining its position or location via an LComsignal received from an LCom-enabled luminaire(s) within the receiverFOV. In some cases, the LCom receiver may also or alternativelydetermine its position or location using GPS, WPS, or some othersuitable positioning system. When no LCom signals are in the FOV of thereceiver and the link is lost to other positioning systems, the receiverINS may be used to augment the receiver positioning. In some cases, theINS mode runs parallel to other positioning techniques to continuouslycalculate the relative position of the receiver. In other cases, the INSmode may be activated after losing the link to other positioningsystems. In any case, the starting point for the INS mode may bedetermined using the last known position of the receiver based on anLCom signal, a GPS signal, a WPS signal, and/or using any other suitablepositioning technique.

Some embodiments relate to allocating LCom data to be transmitted overmultiple colors of light output by multiple LCom-enabled luminaires andtransmitting that LCom data in parallel across the multiple colors oflight using a time division multiple access (TDMA) scheme. In somecases, the disclosed techniques can be used, for example, to allow formultiple LCom-enabled luminaires to communicate simultaneously with asingle receiver device via LCom. In some instances, the disclosedtechniques can be used, for example, to permit a greater quantity ofLCom-enabled luminaires to be disposed within a given space, therebyproviding more accurate positioning, for instance, for indoornavigation. In some cases, the disclosed techniques may be used, forexample, to provide a receiver device with the ability to filtermultiple LCom signals received from different LCom-enabled luminaires.In some instances, the disclosed techniques can be used, for example, toallow multiple LCom channels to be active simultaneously in an LComsystem. In some cases, the disclosed techniques can be used, forexample, to provide a redundant channel to which an LCom-enabledluminaire can switch in order to successfully complete transmission whenan LCom channel is broken.

Some embodiments relate to multiple panel LCom-enabled luminaires. Insome such embodiments, each panel may comprise at least one solid-statelight source, where the light sources are configured to output light.The luminaire may also include at least one modulator configured tomodulate the light output of the light sources to allow for emission ofLCom signals. The luminaire may also include a controller configured tosynchronize timing of the LCom signals. With the timing synchronized,one panel may be configured to emit an LCom signal that is the inverseor duplicate of the LCom signal emitted from another panel. Panel signalinversion may be used to, for example, maintain a relatively constantlevel of light output from the luminaire and/or to create a virtualfiducial to provide orientation information to an LCom receiver. Inaddition, using a multiple panel luminaire to transmit data may resultin improved data transmission rates and transmission reliabilitycompared to, for example, transmitting the same data using a singlepanel luminaire utilizing the same pulsing frequency.

Some embodiments relate to techniques for spatially resolving receivedLCom signals. In an example case where one or more LCom signals are inthe FOV of an LCom receiver, the image representing the FOV may besegmented into non-overlapping cells, such as hexagonal, triangular,rectangular, or circular shaped cells. Each LCom signal may then beinterpreted as a unique pixel cluster comprising one or more of thenon-overlapping cells. In some cases, the LCom signals in the FOV may bereceived from multiple LCom-enabled luminaires and/or a singleLCom-enabled luminaire having multiple light panels. Spatially resolvingreceived LCom signals may be assisted by, for example, filtering outpixels that do not carry an LCom signal, using received signal strengthindicator (RSSI) information, and adjusting for the orientation/tilt ofthe LCom receiver. The benefits of being able to spatially resolvereceived LCom signals can include, but are not limited to, establishinga link with multiple LCom signals within the FOV of a receiver withoutconflict and/or determining the location of those LCom signals,improving signal to noise ratio, augmenting position information,enhancing sampling frequency, and improving communication speed.

As will be appreciated in light of this disclosure, techniques disclosedherein can be utilized in any of a wide range of LCom applications andcontexts. For example, techniques disclosed herein can be utilized, inaccordance with some embodiments, in transmitting location andpositioning information between an LCom-enabled luminaire and a receiverdevice. This information may be utilized, in part or in whole, toprovide for indoor navigation, in accordance with some embodiments. Insome cases, techniques disclosed herein can be utilized as the basis fora positioning and navigation system that may realize improvements inpositioning precision and accuracy, for example, over existing GPS-basedand WPS-based systems. As such, it follows that techniques disclosedherein can be utilized, in accordance with some embodiments, forcommercial endeavors not possible with existing GPS-based andWi-Fi-based approaches. More particularly, while the limited accuracy ofexisting GPS-based and Wi-Fi-based approaches is not sufficient fordirecting a customer to an item of interest on a shelf within a retailstore, techniques disclosed herein can be utilized, in accordance withsome embodiments, to lead customers directly to in-store promotions andother on-shelf items, as desired. Numerous configurations and variationswill be apparent in light of this disclosure.

System Architecture and Operation

FIG. 1 is a block diagram illustrating an example light-basedcommunication (LCom) system 10 configured in accordance with anembodiment of the present disclosure. As can be seen, system 10 mayinclude one or more LCom-enabled luminaires 100 configured forlight-based communicative coupling with a receiver computing device 200via LCom signal(s). As discussed herein, such LCom may be provided, inaccordance with some embodiments, via visible light-based signals. Insome cases, LCom may be provided in only one direction; for instance,LCom data may be passed from a given LCom-enabled luminaire 100 (e.g.,the transmitter) to a computing device 200 (e.g., the receiver), or froma computing device 200 (e.g., the transmitter) to a given LCom-enabledluminaire 100 (e.g., the receiver). In some other cases, LCom may beprovided in both or multiple directions; for instance, LCom data may bepassed between a given LCom-enabled luminaire 100 and a computing device200, where both act in a transmitting and receiving (e.g., transceiver)capacity. In some cases in which system 10 includes a plurality ofLCom-enabled luminaires 100, all (or some sub-set) of thereof may beconfigured for communicative coupling with one another (e.g.,inter-luminaire communication). In accordance with some embodiments,system 10 optionally may include or otherwise be configured forcommunicative coupling, for example, with a server/network 300(discussed below). Communicative coupling may be provided, for example,between server/network 300 and computing device 200 and/or one or moreLCom-enabled luminaires 100, as desired.

FIG. 2A is a block diagram illustrating an LCom-enabled luminaire 100 aconfigured in accordance with an embodiment of the present disclosure.FIG. 2B is a block diagram illustrating an LCom-enabled luminaire 100 bconfigured in accordance with another embodiment of the presentdisclosure. For consistency and ease of understanding of the presentdisclosure, LCom-enabled luminaires 100 a and 100 b hereinafter may becollectively referred to generally as an LCom-enabled luminaire 100,except where separately referenced.

As can be seen, a given LCom-enabled luminaire 100 may include one ormore solid-state light sources 110, in accordance with some embodiments.The quantity, density, and arrangement of solid-state light sources 110utilized in a given LCom-enabled luminaire 100 may be customized, asdesired for a given target application or end-use. A given solid-statelight source 110 may include one or more solid-state emitters, which maybe any of a wide range of semiconductor light source devices, such as,for example: (1) a light-emitting diode (LED); (2) an organiclight-emitting diode (OLED); (3) a polymer light-emitting diode (PLED);and/or (4) a combination of any one or more thereof. A given solid-stateemitter may be configured to emit electromagnetic radiation (e.g.,light), for example, from the visible spectral band and/or otherportions of the electromagnetic spectrum not limited to the infrared(IR) spectral band and/or the ultraviolet (UV) spectral band, as desiredfor a given target application or end-use. In some embodiments, a givensolid-state emitter may be configured for emissions of a singlecorrelated color temperature (CCT) (e.g., a white light-emittingsemiconductor light source). In some other embodiments, however, a givensolid-state emitter may be configured for color-tunable emissions. Forinstance, in some cases, a given solid-state emitter may be amulti-color (e.g., bi-color, tri-color, etc.) semiconductor light sourceconfigured for a combination of emissions, such as: (1) red-green-blue(RGB); (2) red-green-blue-yellow (RGBY); (3) red-green-blue-white(RGBW); (4) dual-white; and/or (5) a combination of any one or morethereof. In some cases, a given solid-state emitter may be configured asa high-brightness semiconductor light source. In some embodiments, agiven solid-state emitter may be provided with a combination of any oneor more of the aforementioned example emissions capabilities. In anycase, a given solid-state emitter can be packaged or non-packaged, asdesired, and in some cases may be populated on a printed circuit board(PCB) or other suitable intermediate/substrate, as will be apparent inlight of this disclosure. In some cases, power and/or controlconnections for a given solid-state emitter may be routed from a givenPCB to a driver 120 (discussed below) and/or other devices/componentry,as desired. Other suitable configurations for the one or moresolid-state emitters of a given solid-state light source 110 will dependon a given application and will be apparent in light of this disclosure.

A given solid-state light source 110 also may include one or more opticsoptically coupled with its one or more solid-state emitters. Inaccordance with some embodiments, the optic(s) of a given solid-statelight source 110 may be configured to transmit the one or morewavelengths of interest of the light (e.g., visible, UV, IR, etc.)emitted by solid-state emitter(s) optically coupled therewith. To thatend, the optic(s) may include an optical structure (e.g., a window,lens, dome, etc.) formed from any of a wide range of optical materials,such as, for example: (1) a polymer, such as poly(methyl methacrylate)(PMMA) or polycarbonate; (2) a ceramic, such as sapphire (Al₂O₃) oryttrium aluminum garnet (YAG); (3) a glass; and/or (4) a combination ofany one or more thereof. In some cases, the optic(s) of a givensolid-state light source 110 may be formed from a single (e.g.,monolithic) piece of optical material to provide a single, continuousoptical structure. In some other cases, the optic(s) of a givensolid-state light source 110 may be formed from multiple pieces ofoptical material to provide a multi-piece optical structure. In somecases, the optic(s) of a given solid-state light source 110 may includeoptical features, such as, for example: (1) an anti-reflective (AR)coating; (2) a reflector; (3) a diffuser; (4) a polarizer; (5) abrightness enhancer; (6) a phosphor material (e.g., which converts lightreceived thereby to light of a different wavelength); and/or (7) acombination of any one or more thereof. In some embodiments, theoptic(s) of a given solid-state light source 110 may be configured, forexample, to focus and/or collimate light transmitted therethrough. Othersuitable types, optical transmission characteristics, and configurationsfor the optic(s) of a given solid-state light source 110 will depend ona given application and will be apparent in light of this disclosure.

In accordance with some embodiments, the one or more solid-state lightsources 110 of a given LCom-enabled luminaire 100 may be electronicallycoupled with a driver 120. In some cases, driver 120 may be anelectronic driver (e.g., single-channel; multi-channel) configured, forexample, for use in controlling one or more solid-state emitters of agiven solid-state light source 110. For instance, in some embodiments,driver 120 may be configured to control the on/off state, dimming level,color of emissions, correlated color temperature (CCT), and/or colorsaturation of a given solid-state emitter (or grouping of emitters). Tosuch ends, driver 120 may utilize any of a wide range of drivingtechniques, including, for example: (1) a pulse-width modulation (PWM)dimming protocol; (2) a current dimming protocol; (3) a triode foralternating current (TRIAC) dimming protocol; (4) a constant currentreduction (CCR) dimming protocol; (5) a pulse-frequency modulation (PFM)dimming protocol; (6) a pulse-code modulation (PCM) dimming protocol;(7) a line voltage (mains) dimming protocol (e.g., dimmer is connectedbefore input of driver 120 to adjust AC voltage to driver 120); and/or(8) a combination of any one or more thereof. Other suitableconfigurations for driver 120 and lighting control/driving techniqueswill depend on a given application and will be apparent in light of thisdisclosure.

As will be appreciated in light of this disclosure, a given solid-statelight source 110 also may include or otherwise be operatively coupledwith other circuitry/componentry, for example, which may be used insolid-state lighting. For instance, a given solid-state light source 110(and/or host LCom-enabled luminaire 100) may be configured to host orotherwise be operatively coupled with any of a wide range of electroniccomponents, such as: (1) power conversion circuitry (e.g., electricalballast circuitry to convert an AC signal into a DC signal at a desiredcurrent and voltage to power a given solid-state light source 110); (2)constant current/voltage driver componentry; (3) transmitter and/orreceiver (e.g., transceiver) componentry; and/or (4) local processingcomponentry. When included, such componentry may be mounted, forexample, on one or more driver 120 boards, in accordance with someembodiments.

As can be seen from FIGS. 2A-2B, a given LCom-enabled luminaire 100 mayinclude memory 130 and one or more processors 140. Memory 130 can be ofany suitable type (e.g., RAM and/or ROM, or other suitable memory) andsize, and in some cases may be implemented with volatile memory,non-volatile memory, or a combination thereof. A given processor 140 maybe configured as typically done, and in some embodiments may beconfigured, for example, to perform operations associated with a givenhost LCom-enabled luminaire 100 and one or more of the modules thereof(e.g., within memory 130 or elsewhere). In some cases, memory 130 may beconfigured to be utilized, for example, for processor workspace (e.g.,for one or more processors 140) and/or to store media, programs,applications, and/or content on a host LCom-enabled luminaire 100 on atemporary or permanent basis.

The one or more modules stored in memory 130 can be accessed andexecuted, for example, by the one or more processors 140 of a givenLCom-enabled luminaire 100. In accordance with some embodiments, a givenmodule of memory 130 can be implemented in any suitable standard and/orcustom/proprietary programming language, such as, for example: (1) C;(2) C++; (3) objective C; (4) JavaScript; and/or (5) any other suitablecustom or proprietary instruction sets, as will be apparent in light ofthis disclosure. The modules of memory 130 can be encoded, for example,on a machine-readable medium that, when executed by a processor 140,carries out the functionality of a given LCom-enabled luminaire 100, inpart or in whole. The computer-readable medium may be, for example, ahard drive, a compact disk, a memory stick, a server, or any suitablenon-transitory computer/computing device memory that includes executableinstructions, or a plurality or combination of such memories. Otherembodiments can be implemented, for instance, with gate-level logic oran application-specific integrated circuit (ASIC) or chip set or othersuch purpose-built logic. Some embodiments can be implemented with amicrocontroller having input/output capability (e.g., inputs forreceiving user inputs; outputs for directing other components) and anumber of embedded routines for carrying out the device functionality.In a more general sense, the functional modules of memory 130 (e.g., oneor more applications 132, discussed below) can be implemented inhardware, software, and/or firmware, as desired for a given targetapplication or end-use.

In accordance with some embodiments, memory 130 may have stored therein(or otherwise have access to) one or more applications 132. In someinstances, a given LCom-enabled luminaire 100 may be configured toreceive input, for example, via one or more applications 132 stored inmemory 130 (e.g., such as a lighting pattern, LCom data, etc.). Othersuitable modules, applications, and data which may be stored in memory130 (or may be otherwise accessible to a given LCom-enabled luminaire100) will depend on a given application and will be apparent in light ofthis disclosure.

In accordance with some embodiments, the one or more solid-state lightsources 110 of a given LCom-enabled luminaire 100 can be electronicallycontrolled, for example, to output light and/or light encoded with LComdata (e.g., an LCom signal). To that end, a given LCom-enabled luminaire100 may include or otherwise be communicatively coupled with one or morecontrollers 150, in accordance with some embodiments. In someembodiments, such as that illustrated in FIG. 2A, a controller 150 maybe hosted by a given LCom-enabled luminaire 100 and operatively coupled(e.g., via a communication bus/interconnect) with the one or moresolid-state light sources 110 (1-N) of that LCom-enabled luminaire 100.In this example case, controller 150 may output a digital control signalto any one or more of the solid-state light sources 110 and may do so,for example, based on wired and/or wireless input received from a givenlocal source (e.g., such as on-board memory 130) and/or remote source(e.g., such as a control interface, optional server/network 300, etc.).As a result, a given LCom-enabled luminaire 100 may be controlled insuch a manner as to output any number of output beams (1-N), which mayinclude light and/or LCom data (e.g., an LCom signal), as desired for agiven target application or end-use.

However, the present disclosure is not so limited. For example, in someother embodiments, such as that illustrated in FIG. 2B, a controller 150may be hosted, in part or in whole, by a given solid-state light source110 of a given LCom-enabled luminaire 100 and operatively coupled (e.g.,via a communication bus/interconnect) with the one or more solid-statelight sources 110. If LCom-enabled luminaire 100 includes a plurality ofsuch solid-state light sources 110 hosting their own controllers 150,then each such controller 150 may be considered, in a sense, amini-controller, providing LCom-enabled luminaire 100 with a distributedcontroller 150. In some embodiments, controller 150 may be populated,for example, on one or more PCBs of the host solid-state light source110. In this example case, controller 150 may output a digital controlsignal to an associated solid-state light source 110 of LCom-enabledluminaire 100 and may do so, for example, based on wired and/or wirelessinput received from a given local source (e.g., such as on-board memory130) and/or remote source (e.g., such as a control interface, optionalserver/network 300, etc.). As a result, LCom-enabled luminaire 110 maybe controlled in such a manner as to output any number of output beams(1-N), which may include light and/or LCom data (e.g., an LCom signal),as desired for a given target application or end-use.

In accordance with some embodiments, a given controller 150 may host oneor more lighting control modules and can be programmed or otherwiseconfigured to output one or more control signals, for example, to adjustthe operation of the solid-state emitter(s) of a given solid-state lightsource 110. For example, in some cases, a given controller 150 may beconfigured to output a control signal to control whether the light beamof a given solid-state emitter is on/off. In some instances, a givencontroller 150 may be configured to output a control signal to controlthe intensity/brightness (e.g., dimming; brightening) of the lightemitted by a given solid-state emitter. In some cases, a givencontroller 150 may be configured to output a control signal to controlthe color (e.g., mixing; tuning) of the light emitted by a givensolid-state emitter. Thus, if a given solid-state light source 110includes two or more solid-state emitters configured to emit lighthaving different wavelengths, the control signal may be used to adjustthe relative brightness of the different solid-state emitters in orderto change the mixed color output by that solid-state light source 110.In some embodiments, controller 150 may be configured to output acontrol signal to encoder 172 (discussed below) to facilitate encodingof LCom data for transmission by a given LCom-enabled luminaire 100. Insome embodiments, controller 150 may be configured to output a controlsignal to modulator 174 (discussed below) to facilitate modulation of anLCom signal for transmission by a given LCom-enabled luminaire 100.Other suitable configurations and control signal output for a givencontroller 150 of a given LCom-enabled luminaire 100 will depend on agiven application and will be apparent in light of this disclosure.

In accordance with some embodiments, a given LCom-enabled luminaire 100may include an encoder 172. In some embodiments, encoder 172 may beconfigured, for example, to encode LCom data in preparation fortransmission thereof by the host LCom-enabled luminaire 100. To thatend, encoder 172 may be provided with any suitable configuration, aswill be apparent in light of this disclosure.

In accordance with some embodiments, a given LCom-enabled luminaire 100may include a modulator 174. In some embodiments, modulator 174 may beconfigured, for example, to modulate an LCom signal in preparation fortransmission thereof by the host LCom-enabled luminaire 100. In someembodiments, modulator 174 may be a single-channel or multi-channelelectronic driver (e.g., driver 120) configured, for example, for use incontrolling the output of the one or more solid-state emitters of agiven solid-state light source 110. In some embodiments, modulator 174may be configured to control the on/off state, dimming level, color ofemissions, correlated color temperature (CCT), and/or color saturationof a given solid-state emitter (or grouping of emitters). To such ends,modulator 174 may utilize any of a wide range of driving techniques,including, for example: (1) a pulse-width modulation (PWM) dimmingprotocol; (2) a current dimming protocol; (3) a triode for alternatingcurrent (TRIAC) dimming protocol; (4) a constant current reduction (CCR)dimming protocol; (5) a pulse-frequency modulation (PFM) dimmingprotocol; (6) a pulse-code modulation (PCM) dimming protocol; (7) a linevoltage (mains) dimming protocol (e.g., dimmer is connected before inputof modulator 174 to adjust AC voltage to modulator 174); and/or (8) anyother suitable lighting control/driving technique, as will be apparentin light of this disclosure. Other suitable configurations andcontrol/driving techniques for modulator 174 will depend on a givenapplication and will be apparent in light of this disclosure.

In accordance with some embodiments, a given LCom-enabled luminaire 100may include a multiplier 176. Multiplier 176 may be configured astypically done, and in some example embodiments may be configured tocombine an input received from an upstream modulator 174 with an inputreceived from an ambient light sensor 165 (discussed below). In someinstances, multiplier 176 may be configured to increase and/or decreasethe amplitude of a signal passing therethrough, as desired. Othersuitable configurations for multiplier 176 will depend on a givenapplication and will be apparent in light of this disclosure.

In accordance with some embodiments, a given LCom-enabled luminaire 100may include an adder 178. Adder 178 may be configured as typically done,and in some example embodiments may be configured to combine an inputreceived from an upstream multiplier 178 with a DC level input. In someinstances, adder 178 may be configured to increase and/or decrease theamplitude of a signal passing therethrough, as desired. Other suitableconfigurations for adder 178 will depend on a given application and willbe apparent in light of this disclosure.

In accordance with some embodiments, a given LCom-enabled luminaire 100may include a digital-to-analog converter (DAC) 180. DAC 180 may beconfigured as typically done, and in some example embodiments may beconfigured to convert a digital control signal into an analog controlsignal to be applied to a given solid-state light source 110 of the hostLCom-enabled luminaire 100 to output an LCom signal therefrom. Othersuitable configurations for DAC 180 will depend on a given applicationand will be apparent in light of this disclosure.

As previously noted, a given LCom-enabled luminaire 100 may beconfigured, in accordance with some embodiments, to output light and/orlight encoded with LCom data (e.g., an LCom signal). FIG. 3 illustratesan example arbitrary LCom signal as may be transmitted by anLCom-enabled luminaire 100, in accordance with an embodiment of thepresent disclosure. As can be seen here, LCom-enabled luminaire 100 maybe configured, in accordance with some embodiments, to transmit a givenLCom signal at a given transmission rate over a given time interval(t₁-t₀). In some cases, a given LCom-enabled luminaire 100 may beconfigured to repeatedly output its one or more LCom signals. In anycase, the transmission rate may be customized, as desired for a giventarget application or end-use.

In accordance with some embodiments, a given LCom-enabled luminaire 100may include one or more sensors 160. In some embodiments, a givenLCom-enabled luminaire 100 optionally may include an altimeter 161. Whenincluded, altimeter 161 may be configured as typically done, and in someexample embodiments may be configured to aid in determining the altitudeof a host LCom-enabled luminaire 100 with respect to a given fixed level(e.g., a floor, a wall, the ground, or other surface). In someembodiments, a given LCom-enabled luminaire 100 optionally may include ageomagnetic sensor 163. When included, geomagnetic sensor 163 may beconfigured as typically done, and in some example embodiments may beconfigured to determine the orientation and/or movement of a hostLCom-enabled luminaire 100 relative to a geomagnetic pole (e.g.,geomagnetic north) or other desired heading, which may be customized asdesired for a given target application or end-use. In some embodiments,a given LCom-enabled luminaire 100 optionally may include an ambientlight sensor 165. When included, ambient light sensor 165 may beconfigured as typically done, and in some example embodiments may beconfigured to detect and measure ambient light levels in the surroundingenvironment of the host LCom-enabled luminaire 100. In some cases,ambient light sensor 165 may be configured to output a signal, forexample, to a multiplier 176 of LCom-enabled luminaire 100. In someembodiments, a given LCom-enabled luminaire 100 optionally may include agyroscopic sensor 167. When included, gyroscopic sensor 167 may beconfigured as typically done, and in some example embodiments may beconfigured to determine the orientation (e.g., roll, pitch, and/or yaw)of the host LCom-enabled luminaire 100. In some embodiments, a givenLCom-enabled luminaire 100 optionally may include an accelerometer 169.When included, accelerometer 169 may be configured as typically done,and in some example embodiments may be configured to detect motion ofthe host LCom-enabled luminaire 100. In any case, a given sensor 160 ofa given host LCom-enabled luminaire 100 may include mechanical and/orsolid-state componentry, as desired for a given target application orend-use. Also, it should be noted that the present disclosure is not solimited only to these example optional sensors 160, as additional and/ordifferent sensors 160 may be provided, as desired for a given targetapplication or end-use, in accordance with some other embodiments.Numerous configurations will be apparent in light of this disclosure.

In accordance with some embodiments, a given LCom-enabled luminaire 100may include a communication module 170, which may be configured forwired (e.g., Universal Serial Bus or USB, Ethernet, FireWire, etc.)and/or wireless (e.g., Wi-Fi, Bluetooth, etc.) communication, asdesired. In accordance with some embodiments, communication module 170may be configured to communicate locally and/or remotely utilizing anyof a wide range of wired and/or wireless communications protocols,including, for example: (1) a digital multiplexer (DMX) interfaceprotocol; (2) a Wi-Fi protocol; (3) a Bluetooth protocol; (4) a digitaladdressable lighting interface (DALI) protocol; (5) a ZigBee protocol;and/or (6) a combination of any one or more thereof. It should be noted,however, that the present disclosure is not so limited to only theseexample communications protocols, as in a more general sense, and inaccordance with some embodiments, any suitable communications protocol,wired and/or wireless, standard and/or custom/proprietary, may beutilized by communication module 170, as desired for a given targetapplication or end-use. In some instances, communication module 170 maybe configured to facilitate inter-luminaire communication betweenLCom-enabled luminaires 100. To that end, communication module 170 maybe configured to use any suitable wired and/or wireless transmissiontechnologies (e.g., radio frequency, or RF, transmission; infrared, orIR, light modulation; etc.), as desired for a given target applicationor end-use. Other suitable configurations for communication module 170will depend on a given application and will be apparent in light of thisdisclosure.

FIG. 4 illustrates an example computing device 200 configured inaccordance with an embodiment of the present disclosure. As discussedherein, computing device 200 may be configured, in accordance with someembodiments: (1) to detect the light pulses of an LCom signal emitted bya transmitting LCom-enabled luminaire 100; and (2) to decode the LComdata from a detected LCom signal. To these ends, computing device 200can be any of a wide range of computing platforms, mobile or otherwise.For example, in accordance with some embodiments, computing device 200can be, in part or in whole: (1) a laptop/notebook computer orsub-notebook computer; (2) a tablet or phablet computer; (3) a mobilephone or smartphone; (4) a personal digital assistant (PDA); (5) aportable media player (PMP); (6) a cellular handset; (7) a handheldgaming device; (8) a gaming platform; (9) a desktop computer; (10) atelevision set; (11) a wearable or otherwise body-borne computingdevice, such as a smartwatch, smart glasses, or smart headgear; and/or(12) a combination of any one or more thereof. Other suitableconfigurations for computing device 200 will depend on a givenapplication and will be apparent in light of this disclosure.

As can be seen from FIG. 4, computing device 200 may include memory 210and one or more processors 220. Memory 210 can be of any suitable type(e.g., RAM and/or ROM, or other suitable memory) and size, and in somecases may be implemented with volatile memory, non-volatile memory, or acombination thereof. A given processor 220 of computing device 200 maybe configured as typically done, and in some embodiments may beconfigured, for example, to perform operations associated with computingdevice 200 and one or more of the modules thereof (e.g., within memory210 or elsewhere). In some cases, memory 210 may be configured to beutilized, for example, for processor workspace (e.g., for one or moreprocessors 220) and/or to store media, programs, applications, and/orcontent on computing device 200 on a temporary or permanent basis.

The one or more modules stored in memory 210 can be accessed andexecuted, for example, by the one or more processors 220 of computingdevice 200. In accordance with some embodiments, a given module ofmemory 210 can be implemented in any suitable standard and/orcustom/proprietary programming language, such as, for example: (1) C;(2) C++; (3) objective C; (4) JavaScript; and/or (5) any other suitablecustom or proprietary instruction sets, as will be apparent in light ofthis disclosure. The modules of memory 210 can be encoded, for example,on a machine-readable medium that, when executed by a processor 220,carries out the functionality of computing device 200, in part or inwhole. The computer-readable medium may be, for example, a hard drive, acompact disk, a memory stick, a server, or any suitable non-transitorycomputer/computing device memory that includes executable instructions,or a plurality or combination of such memories. Other embodiments can beimplemented, for instance, with gate-level logic or anapplication-specific integrated circuit (ASIC) or chip set or other suchpurpose-built logic. Some embodiments can be implemented with amicrocontroller having input/output capability (e.g., inputs forreceiving user inputs; outputs for directing other components) and anumber of embedded routines for carrying out the device functionality.In a more general sense, the functional modules of memory 210 (e.g.,such as OS 212, UI 214, and/or one or more applications 216, eachdiscussed below) can be implemented in hardware, software, and/orfirmware, as desired for a given target application or end-use.

In accordance with some embodiments, memory 210 may include an operatingsystem (OS) 212. OS 212 can be implemented with any suitable OS, mobileor otherwise, such as, for example: (1) Android OS from Google, Inc.;(2) iOS from Apple, Inc.; (3) BlackBerry OS from BlackBerry Ltd.; (4)Windows Phone OS from Microsoft Corp; (5) Palm OS/Garnet OS from Palm,Inc.; (6) an open source OS, such as Symbian OS; and/or (7) acombination of any one or more thereof. As will be appreciated in lightof this disclosure, OS 212 may be configured, for example, to aid inprocessing LCom data during its flow through computing device 200. Othersuitable configurations and capabilities for OS 212 will depend on agiven application and will be apparent in light of this disclosure.

In accordance with some embodiments, computing device 200 may include auser interface (UI) module 214. In some cases, UI 214 can be implementedin memory 210 (e.g., as generally shown in FIG. 4), whereas in someother cases, UI 214 can be implemented in a combination of locations(e.g., at memory 210 and at display 230, discussed below), therebyproviding UI 214 with a given degree of functional distributedness. UI214 may be configured, in accordance with some embodiments, to present agraphical UI (GUI) at display 230 that is configured, for example, toaid in carrying out any of the various LCom-related techniques discussedherein. Other suitable configurations and capabilities for UI 214 willdepend on a given application and will be apparent in light of thisdisclosure.

In accordance with some embodiments, memory 210 may have stored therein(or otherwise have access to) one or more applications 216. In someinstances, computing device 200 may be configured to receive input, forexample, via one or more applications 216 stored in memory 210 (e.g.,such as an indoor navigation application). Other suitable modules,applications, and data which may be stored in memory 210 (or may beotherwise accessible to computing device 200) will depend on a givenapplication and will be apparent in light of this disclosure.

As can be seen further from FIG. 4, computing device 200 may include adisplay 230, in accordance with some embodiments. Display 230 can be anyelectronic visual display or other device configured to display orotherwise generate an image (e.g., image, video, text, and/or otherdisplayable content) there at. In some instances, display 230 may beintegrated, in part or in whole, with computing device 200, whereas insome other instances, display 230 may be a stand-alone componentconfigured to communicate with computing device 200 using any suitablewired and/or wireless communications means.

In some cases, display 230 optionally may be a touchscreen display orother touch-sensitive display. To that end, display 230 may utilize anyof a wide range of touch-sensing techniques, such as, for example: (1)resistive touch-sensing; (2) capacitive touch-sensing; (3) surfaceacoustic wave (SAW) touch-sensing; (4) infrared (IR) touch-sensing; (5)optical imaging touch-sensing; and/or (6) a combination of any one ormore thereof. In a more general sense, and in accordance with someembodiments, an optionally touch-sensitive display 230 generally may beconfigured to detect or otherwise sense direct and/or proximate contactfrom a user's finger, stylus, or other suitable implement at a givenlocation of that display 230. In some cases, an optionallytouch-sensitive display 230 may be configured to translate such contactinto an electronic signal that can be processed by computing device 200(e.g., by the one or more processors 220 thereof) and manipulated orotherwise used to trigger a given GUI action. In some cases, atouch-sensitive display 230 may facilitate user interaction withcomputing device 200 via the GUI presented by such display 230. Numeroussuitable configurations for display 230 will be apparent in light ofthis disclosure.

In accordance with some embodiments, computing device 200 may include acommunication module 240, which may be configured for wired (e.g.,Universal Serial Bus or USB, Ethernet, FireWire, etc.) and/or wireless(e.g., Wi-Fi, Bluetooth, etc.) communication using any suitable wiredand/or wireless transmission technologies (e.g., radio frequency, or RF,transmission; infrared, or IR, light modulation; etc.), as desired. Inaccordance with some embodiments, communication module 240 may beconfigured to communicate locally and/or remotely utilizing any of awide range of wired and/or wireless communications protocols, including,for example: (1) a digital multiplexer (DMX) interface protocol; (2) aWi-Fi protocol; (3) a Bluetooth protocol; (4) a digital addressablelighting interface (DALI) protocol; (5) a ZigBee protocol; (6) a nearfield communication (NFC) protocol; (7) a local area network (LAN)-basedcommunication protocol; (8) a cellular-based communication protocol; (9)an Internet-based communication protocol; (10) a satellite-basedcommunication protocol; and/or (11) a combination of any one or morethereof. It should be noted, however, that the present disclosure is notso limited to only these example communications protocols, as in a moregeneral sense, and in accordance with some embodiments, any suitablecommunications protocol, wired and/or wireless, standard and/orcustom/proprietary, may be utilized by communication module 240, asdesired for a given target application or end-use. In some instances,communication module 240 may be configured to communicate with one ormore LCom-enabled luminaires 100. In some cases, communication module240 of computing device 200 and communication module 170 of a givenLCom-enabled luminaire 100 may be configured to utilize the samecommunication protocol. In some cases, communication module 240 may beconfigured to communicate with a server/network 300 (discussed below).Other suitable configurations for communication module 240 will dependon a given application and will be apparent in light of this disclosure.

Also, as can be seen from FIG. 4, computing device 200 may include oneor more image capture devices 250, such as a front-facing image capturedevice 252 and/or a rear-facing image capture device 254, in accordancewith some embodiments. For consistency and ease of understanding of thepresent disclosure, front-facing image capture device 252 andrear-facing image capture device 254 hereinafter may be collectivelyreferred to generally as an image capture device 250, except whereseparately referenced.

A given image capture device 250 can be any device configured to capturedigital images, such as a still camera (e.g., a camera configured tocapture still photographs) or a video camera (e.g., a camera configuredto capture moving images comprising a plurality of frames). In somecases, a given image capture device 250 may include components such as,for instance, an optics assembly, an image sensor, and/or an image/videoencoder, and may be integrated, in part or in whole, with computingdevice 200. These components (and others, if any) of a given imagecapture device 250 may be implemented in any combination of hardware,software, and/or firmware, as desired for a given target application orend-use. A given image capture device 250 can be configured to operateusing light, for example, in the visible spectrum and/or other portionsof the electromagnetic spectrum not limited to the infrared (IR)spectrum, ultraviolet (UV) spectrum, etc. In some instances, a givenimage capture device 250 may be configured to continuously acquireimaging data. As described herein, a given image capture device 250 ofcomputing device 200 may be configured, in accordance with someembodiments, to detect the light and/or LCom signal output of atransmitting LCom-enabled luminaire 100. In some instances, a givenimage capture device 250 may be, for example, a camera like onetypically found in smartphones or other mobile computing devices. Othersuitable configurations for a given image capture device 250 (e.g.,front-facing image capture device 252; rear-facing image capture device254) of computing device 200 will depend on a given application and willbe apparent in light of this disclosure.

In accordance with some embodiments, computing device 200 may includeone or more sensors 260. In some embodiments, computing device 200optionally may include a geomagnetic sensor 263. When included,geomagnetic sensor 263 may be configured as typically done, and in someexample embodiments may be configured to determine the orientationand/or movement of a host computing device 200 relative to a geomagneticpole (e.g., geomagnetic north) or other desired heading, which may becustomized as desired for a given target application or end-use. In someembodiments, computing device 200 optionally may include an ambientlight sensor 265. When included, ambient light sensor 265 may beconfigured as typically done, and in some example embodiments may beconfigured to detect and measure ambient light levels in the surroundingenvironment of the host computing device 200. In some embodiments,computing device 200 optionally may include a gyroscopic sensor 267.When included, gyroscopic sensor 267 may be configured as typicallydone, and in some example embodiments may be configured to determine theorientation (e.g., roll, pitch, and/or yaw) of the host computing device200. In some embodiments, computing device 200 optionally may include anaccelerometer 269. When included, accelerometer 269 may be configured astypically done, and in some example embodiments may be configured todetect motion of the host computing device 200. In any case, a givensensor 260 of a given host computing device 200 may include mechanicaland/or solid-state componentry, as desired for a given targetapplication or end-use. Also, it should be noted that the presentdisclosure is not so limited only to these example optional sensors 260,as additional and/or different sensors 260 may be provided, as desiredfor a given target application or end-use, in accordance with some otherembodiments. Numerous configurations will be apparent in light of thisdisclosure.

In accordance with some embodiments, computing device 200 may include orotherwise be communicatively coupled with one or more controllers 270. Agiven controller 270 may be configured to output one or more controlsignals to control any one or more of the various components/modules ofcomputing device 200 and may do so, for example, based on wired and/orwireless input received from a given local source (e.g., such ason-board memory 210) and/or remote source (e.g., such as a controlinterface, optional server/network 300, etc.). In accordance with someembodiments, a given controller 270 may host one or more control modulesand can be programmed or otherwise configured to output one or morecontrol signals, for example, to adjust the operation of a given portionof computing device 200. For example, in some cases, a given controller270 may be configured to output a control signal to control operation ofa given image capture device 250 (e.g., front-facing image capturedevice 252 and/or rear-facing image capture device 254). In someinstances, a given controller 270 may be configured to output a controlsignal to control operation of one or more sensors 260. Other suitableconfigurations and control signal output for a given controller 270 ofcomputing device 200 will depend on a given application and will beapparent in light of this disclosure.

As can be seen further from FIG. 4, computing device 200 may include anaudio output device 280, in accordance with some embodiments. Audiooutput device 280 can be, for example, a speaker or any other devicecapable of producing sound from an audio data signal, in accordance withsome embodiments. Audio output device 280 can be configured, forexample, to reproduce sounds local to and/or received by its hostcomputing device 200. In some instances, audio output device 280 may beintegrated, in part or in whole, with computing device 200, whereas insome other instances, audio output device 280 may be a stand-alonecomponent configured to communicate with computing device 200 using anysuitable wired and/or wireless communications means, as desired. Othersuitable types and configurations for audio output device 280 willdepend on a given application and will be apparent in light of thisdisclosure.

Server/network 300 can be any suitable public and/or privatecommunications network. For instance, in some cases, server/network 300may be a private local area network (LAN) operatively coupled to a widearea network (WAN), such as the Internet. In some cases, server/network300 may include one or more second-generation (2G), third-generation(3G), and/or fourth-generation (4G) mobile communication technologies.In some cases, server/network 300 may include a wireless local areanetwork (WLAN) (e.g., Wi-Fi wireless data communication technologies).In some instances, server/network 300 may include Bluetooth wirelessdata communication technologies. In some cases, server/network 300 mayinclude supporting infrastructure and/or functionalities, such as aserver and a service provider, but such features are not necessary tocarry out communication via server/network 300. In some instances,computing device 200 may be configured for communicative coupling, forexample, with a server/network 300 and one or more LCom-enabledluminaires 100. In some cases, computing device 200 may be configured toreceive data from server/network 300, for example, which serves tosupplement LCom data received by computing device 200 from a givenLCom-enabled luminaire 100. In some instances, computing device 200 maybe configured to receive data (e.g., such as position, ID, and/or otherdata pertaining to a given LCom-enabled luminaire 100) fromserver/network 300 that facilitates indoor navigation via one or moreLCom-enabled luminaires 100. In some cases, server/network 300 mayinclude or otherwise have access to one or more lookup tables of datathat may be accessed by a computing device 200 communicatively coupledtherewith. Numerous configurations for server/network 300 will beapparent in light of this disclosure.

Techniques for Enhancing Baud Rate in LCom

As previously noted, there are a number of non-trivial challengesassociated with modulating data over light and transmitting it intospace for LCom. For example, to prevent or otherwise minimize visualartifacts and other perceivable changes in light output, it may bedesirable to have the LCom light source transmit at a sufficiently highspeed. However, effective detection of the modulated light by a givenreceiver device depends on whether that device has sufficient receptioncapabilities. Currently available smartphone cameras typically have amaximum frame rate of 30 frames/second (FPS) or 60 FPS, providing onlyvery limited low-speed reception capabilities. As such, there iscurrently no known way to effectively utilize existing smartphone camerahardware in obtaining data modulated over light without either: (1)making a change in the transmitted light output, which would beperceivable to the user and any bystanders; or (2) adding costly,specialized receiver hardware to the receiver device.

Thus, and in accordance with some embodiments, techniques are disclosedfor coding LCom data in a manner that allows for detection thereof via afront-facing image capture device 252 such as, for example, a standardlow-speed smartphone camera having a frame rate of 30 FPS. In somecases, the disclosed techniques can be used, for example, in encodingand decoding LCom data in a manner that: (1) prevents or otherwiseminimizes perceivable flicker of the light output by a transmittingLCom-enabled luminaire 100; and/or (2) avoids or otherwise reduces aneed for additional, specialized receiver hardware at computing device200. In some cases, the disclosed techniques can be used, for example,to enhance the baud rate between a transmitting LCom-enabled luminaire100 and a receiving computing device 200. For instance, if front-facingimage capture device 252 is a typical smartphone front-facing cameraconfigured to capture images at 30 FPS at VGA resolution (640×480pixels), and if a standard RGB color profile is utilized, then eachframe captured by that front-facing image capture device 252 is about900 KB of image data (640 pixels×480 pixels×3 colors). Thus, at a framerate of 30 FPS, that front-facing image capture device 252 may captureabout 27 MB of raw image data each second, in accordance with an exampleembodiment.

FIG. 5A is a flow diagram illustrating an example process of coding LComdata via a rolling shutter coding scheme, in accordance with anembodiment of the present disclosure. As can be seen, the flow may beginas in block 501 with performing a rolling shutter image captureinclusive of an LCom-enabled luminaire 100 transmitting an LCom signal.The rolling shutter image capture may be performed, for example, viafront-facing image capture device 252 of computing device 200. Theduration of the rolling shutter image capture may be customized asdesired for a given target application or end-use, and in some cases maybe at least as long as the time interval (t₁-t₀) that it takes forLCom-enabled luminaire 100 to make one complete transmission of its LComdata before repeating transmission (e.g., as discussed above withrespect to FIG. 3).

Thereafter, the flow may continue as in block 503 with decoding any LComdata present in each captured image frame. During the rolling shutterimage capture, front-facing image capture device 252 may capture aplurality of image frames (Frames 1-N) at a given frame rate (Nframes/second). In accordance with some embodiments, front-facing imagecapture device 252 may be configured to capture images at a frame rate,for example, in the range of about 24-60 FPS, or greater. As can be seenfrom FIG. 5B, which illustrates an example rolling shutter image capturevia front-facing image capture device 252 in accordance with anembodiment of the present disclosure, while only partial LCom data maybe captured by front-facing image capture device 252 at any givencaptured image frame, the plurality of captured image frames (Frames1-N) contains the full LCom data in the aggregate. Thus, if front-facingimage capture device 252 performs a rolling shutter image capture, forexample, at a frame rate of 30 FPS, then over a time interval of 1second, 30 frames of partial LCom data are captured, those image framescontaining the full LCom data in the aggregate.

Thereafter, the flow may continue as in block 505 with reconstructingthe full LCom data of the transmitted LCom signal using partial LComdata decoded from each captured image frame. As only partial LCom datais received per captured image frame, over a sufficiently long timeinterval of performing the rolling shutter image capture, the full LComdata packet can be reconstructed utilizing all (or some sub-set) of thepartial LCom data captured by front-facing image capture device 252 overthe plurality of image frames (1-N). Thus, if a transmittingLCom-enabled luminaire 100 repeatedly transmits its LCom signal at 30FPS, then a receiving computing device 200 may reconstruct a full LComdata packet, for example, from 60 image frames of partial LCom datareceived over a time interval of 2 seconds. Reconstruction of the fullLCom data may be performed, for example, via a processor 220 ofcomputing device 200, and in some cases may be aided by an application216 hosted thereby (e.g., in memory 210) or otherwise accessiblethereto.

FIG. 5C is a flow diagram illustrating an example process of coding LComdata via an undersampling/aliasing scheme, in accordance with anembodiment of the present disclosure. As can be seen, the flow may beginas in block 511 with capturing an image inclusive of an LCom-enabledluminaire transmitting an LCom signal. In accordance with an embodiment,the image capture may be performed, for example, via front-facing imagecapture device 252 of computing device 200.

Thereafter, the flow may continue as in block 513 with sampling thecaptured image data at the modulation frequency at which the LCom dataof the LCom signal is encoded, but undersampling at least one pixel. Inaccordance with some embodiments, LCom-enabled luminaire 100 may beconfigured to modulate its LCom signal (e.g., via modulator 174) withoutfiltering at a given fixed modulation frequency. For instance, considerFIG. 5D, which illustrates an example modulation signal of fixedmodulation frequency, in accordance with an embodiment of the presentdisclosure. As can be seen here, in some cases, a modulation frequencyof greater than or equal to about 1 kHz may be utilized by LCom-enabledluminaire 100 in modulating its LCom data. The present disclosure is notso limited only to this example modulation frequency range, however, asin a more general sense, and in accordance with some embodiments, themodulation frequency may be any suitable frequency sufficient to preventor otherwise minimize perceivable flicker (e.g., perceivable to a useror any bystanders). In some instances, the fixed modulation frequencyoptionally may be adjusted to account for jitter (E).

Normally, to reconstruct an unknown analog signal in accordance with theNyquist criterion, that signal must be sampled at a frequency greaterthan twice the highest frequency component in the signal. However, ifthe encoding scheme (e.g., modulation frequency) is known beforehand,then information from the analog LCom signal can be captured and decodedutilizing a much lower sampling rate than normally would be required.Thus, in accordance with some embodiments, the LCom data transmitted byLCom-enabled luminaire 100 may be sampled by computing device 200 at thesame modulation frequency at which the LCom data was encoded byLCom-enabled luminaire 100, while undersampling at least one designatedpixel. In accordance with some embodiments, the undersampling rate maybe, for example, in the range of about 24-60 FPS. In some cases in whichfront-facing image capture device 252 is, for example, a standardlow-speed smartphone camera, the undersampling rate may be 30 FPS or 60FPS. Other suitable undersampling rates will depend on a givenapplication and will be apparent in light of this disclosure.

Thereafter, the flow may continue as in block 515 with reconstructingthe full LCom data of the transmitted LCom signal using detectedfluctuations of the at least one undersampled pixel. As previouslynoted, if the modulation frequency of LCom-enabled luminaire 100 isknown beforehand, then the Nyquist criterion can be violated to extractthe full LCom data from the LCom signal received by front-facing imagecapture device 252. Given that the LCom signal transmitted byLCom-enabled luminaire 100 may be repeated (e.g., as discussed abovewith respect to FIG. 3), the entire LCom data packet may be obtained byfront-facing image capture device 252 over a given period of time bydetecting the optical intensity of its pixel(s) where the image of anLCom-enabled luminaire 100 is focused and analyzing detectedfluctuations of the undersampled pixel(s). More particularly, given thatthe LCom signal is repeatedly transmitted, a beat frequency betweenLCom-enabled luminaire 100 and front-facing image capture device 252 maybe achieved, at which point computing device 200 may receive the LComdata in a raster scanning manner and reassemble that LCom data into theLCom data packets transmitted by LCom-enabled luminaire 100.Reconstruction of the full LCom data may be performed, for example, viaa processor 220 of computing device 200, and in some cases may be aidedby an application 216 hosted thereby (e.g., in memory 210) or otherwiseaccessible thereto.

Numerous variations on the methodologies of FIGS. 5A and 5C will beapparent in light of this disclosure. As will be appreciated, and inaccordance with some embodiments, each of the functional boxes (e.g.,501; 503; 505) shown in FIG. 5A and each of the functional boxes (e.g.,511; 513; 515) shown in FIG. 5C can be implemented, for example, as amodule or sub-module that, when executed by one or more processors 220or otherwise operated, causes the associated functionality as describedherein to be carried out. The modules/sub-modules may be implemented,for instance, in software (e.g., executable instructions stored on oneor more computer readable media), firmware (e.g., embedded routines of amicrocontroller or other device which may have I/O capacity forsoliciting input from a user and providing responses to user requests),and/or hardware (e.g., gate level logic, field-programmable gate array,purpose-built silicon, etc.).

In accordance with some embodiments, operations associated with therolling shutter coding scheme and/or the undersampling/aliasing codingscheme described herein can be implemented, for example, utilizing oneor more applications 216 on computing device 200 (e.g., within memory210) or otherwise accessible thereto. As hardware components improveover time, both with respect to the transmitter side (e.g., LCom-enabledluminaire 100) and the receiver side (e.g., computing device 200),features such as high-speed data streaming can be implemented, forexample, via software, firmware, hardware, or a combination thereof, inaccordance with some embodiments.

As previously noted, in some cases, the disclosed techniques can beused, for example, to allow for detection of data modulation over lightfor LCom by a given computing device 200 utilizing hardware present inor otherwise already native to that computing device 200. For instance,the disclosed techniques can be used, in an example case, to allow for astandard low-speed camera of a smartphone or other mobile computingdevice to effectively engage in LCom with one or more LCom-enabledluminaires 100. In some cases, the techniques discussed herein may beprovided, in part or in whole, via software without the use ofspecialized hardware. However, the present disclosure is not so limited,as in some other cases, additional and/or different hardware fordetection of LCom data modulation over light may be operatively coupledwith computing device 200. For instance, in accordance with someembodiments, a photosensor dongle, a color sensor dongle, or othersuitable hardware optionally may be communicatively coupled withcomputing device 200, as desired for a given target application orend-use. In some such instances, the additional/different light-sensinghardware may be used in conjunction with hardware present in orotherwise already native to the computing device 200 (e.g., such asfront-facing image capture device 252), whereas in some other instances,the additional/different light-sensing hardware may be used exclusive ofor otherwise in preference over native componentry of computing device200.

Techniques for Adaptive Light Modulation in LCom

Existing approaches to light-based communication utilize fixedmodulation depth. However, given that the selected fixed modulationdepth of these approaches must guarantee acceptable SNR under worst-caseconditions, it is thus not optimal (that is, not minimal) in morefavorable situations and environments. Typically, full-amplitude lightmodulation for light-based communication negatively impacts emitterefficiency and emissions quality (e.g., as assessed by the flickervalue). High-frequency light modulation can reduce this negative impacton light quality, but may not be applicable when relying onlow-bandwidth receivers. Also, high-frequency modulation puts additionaland stricter requirements, such as load transient response time, ondriver electronics, which are more complex and expensive to implement insuch approaches.

Thus, and in accordance with some embodiments, techniques are disclosedfor dynamically adjusting light modulation depth based, at least inpart, on ambient light levels. Under the disclosed adaptive lightmodulation scheme, a given LCom-enabled luminaire 100 may be configuredto adjust the modulation depth dynamically and/or control thesignal-to-noise ratio (SNR) such that the average light signal is keptconstant, regardless of what LCom data is being transmitted. Forexample, consider FIG. 6A, which is a graph illustrating light level asa function of time for an example case of adaptive modulation depth, inaccordance with an embodiment of the present disclosure. In accordancewith some embodiments, the light modulation depth may be adjusteddynamically, for example, according to a given minimum light modulationdepth assessed by measuring the ambient lighting conditions of theenvironment of the LCom-enabled luminaire 100. In some instances, anoptimal or other target SNR can be provided using the disclosedtechniques. In a more general sense, and in accordance with someembodiments, the modulation depth associated with the pulsing lightsignal may be varied, in part or in whole, based on the ambient lightlevel detected, for example, via an ambient light sensor 265.

In accordance with some embodiments, LCom-enabled luminaire 100 mayinclude control circuitry configured to dynamically adjust lightmodulation depth, for example, based on input parameters derived fromambient light measurements. For example, consider FIG. 6B, which is ablock diagram illustrating a control loop of an LCom-enabled luminaire100 configured in accordance with an embodiment of the presentdisclosure. As can be seen, in some embodiments, the control loop mayinclude one or more of: (1) an encoder 172; (2) a modulator 174; (3) anambient light sensor 165; (4) a multiplier 176; (5) an adder 178; and(6) a DAC 180. In accordance with some embodiments, the control loop maybe communicatively coupled with one or more solid-state light sources110. In accordance with some embodiments, the control loop may beconfigured to adaptively change the modulation amplitude of LCom-enabledluminaire 100 to keep the SNR substantially constant (e.g., preciselyconstant or otherwise within a given tolerance). In this manner,LCom-enabled luminaire 100 may provide for LCom, for example, even whenthe ambient light level is not constant. In some cases, a constant SNRmay be maintained for the pulsing light signal over a range ofmodulation depths, in accordance with some embodiments.

FIG. 6C is a flow diagram illustrating a process of dynamicallyadjusting the modulation depth of an LCom signal, in accordance with anembodiment of the present disclosure. As can be seen, the flow may beginas in block 601 with encoding a digital control signal with LCom data tobe transmitted. The LCom data may be provided by a local source (e.g.,memory 130) and/or a remote source (e.g., a control interface, optionalserver/network 300, or other provider via any suitable wired and/orwireless communication means). Encoding may be performed, in part or inwhole, via encoder 172 of a given LCom-enabled luminaire 100. In someembodiments, encoder 172 may be configured to encode the LCom data, forexample, using Manchester coding (e.g., Phase Encoding or PE). WithManchester coding, the encoding of each LCom data bit may have at leastone transition and may occupy the same time. As such, it may have no DCcomponent and may be self-clocking, which means that a clock signal canbe recovered from the encoded LCom data. In accordance with someembodiments, use of Manchester coding in the disclosed adaptive lightmodulation scheme may ensure a constant average light level, regardlessof what LCom data is transmitted. It should be noted, however, that thepresent disclosure is not so limited only to use of Manchester coding,as in accordance with some other embodiments, other types of linecoding, such as bi-polar encoding or return-to-zero (RZ) encoding, maybe utilized in encoding of the digital control signal with LCom data, asdesired for a given target application or end-use.

Thereafter, the flow may continue as in block 603 with modulating theresultant digital control signal. Modulation may be performed, in partor in whole, via modulator 174 of LCom-enabled luminaire 100, inaccordance with some embodiments. In some embodiments, modulator 174 maybe, for example, a solid-state light source driver (e.g., such as driver120) configured to output a pulse-width modulation (PWM) signal. Othersuitable configurations and outputs for modulator 174 will depend on agiven application and will be apparent in light of this disclosure.

Thereafter, the flow may continue as in block 605 with adjusting theresultant digital control signal based on detected ambient light levels.In accordance with some embodiments, detection of ambient light levelsmay be performed, for example, via ambient light sensor 165 of a givenLCom-enabled luminaire 100. In accordance with some embodiments, theamplitude of the signal output (e.g., PWM signal) of modulator 174 maybe varied, for example, by multiplying the control signal by a factorthat is directly proportional to the amount of ambient light detected byambient light sensor 165 of LCom-enabled luminaire 100. Moreparticularly, the modulated digital control signal may be multiplied,for example, with binary encoded LCom data (e.g., as encoded by encoder172), in accordance with some embodiments. Such adjustments of themodulated control signal may be performed, for example, via multiplier176 of LCom-enabled luminaire 100. Other suitable signal adjustmentsthat may be provided via modulator 174, ambient light sensor 165, and/ormultiplier 176 will depend on a given application and will be apparentin light of this disclosure.

Thereafter, the flow may continue as in block 607 with adjusting theresultant digital control signal based on the DC level of LCom-enabledluminaire 100. Adjustment may be performed, in part or in whole, viaadder 178 of a given LCom-enabled luminaire 100, in accordance with someembodiments. As will be appreciated in light of this disclosure, the DClevel may be set at any threshold value suitable for identifying theencoded LCom data within the encoded, modulated digital control signaland can be customized, as desired for a given target application orend-use.

Thereafter, the flow may continue as in block 609 with converting theresultant digital control signal to an analog control signal. Analogconversion may be performed, in part or in whole, via DAC 180 ofLCom-enabled luminaire 100, in accordance with some embodiments.Thereafter, the flow may continue as in block 611 with output ofresultant analog control signal to a given solid-state light source 110of LCom-enabled luminaire 100. In turn, that solid-state light source110 may output one or more LCom signals, in accordance with someembodiments. In some cases, a given LCom signal (e.g., the encoded LComdata dynamically modulated over light) output by LCom-enabled luminaire100 may be transmitted to a computing device 200 configured to detectand decode such an LCom signal.

Numerous variations on the methodology of FIG. 6C will be apparent inlight of this disclosure. As will be appreciated, and in accordance withsome embodiments, each of the functional boxes (e.g., 601; 603; 605:607; 609; 611) shown in FIG. 6C can be implemented, for example, as amodule or sub-module that, when executed by one or more processors 140or otherwise operated, causes the associated functionality as describedherein to be carried out. The modules/sub-modules may be implemented,for instance, in software (e.g., executable instructions stored on oneor more computer readable media), firmware (e.g., embedded routines of amicrocontroller or other device which may have I/O capacity forsoliciting input from a user and providing responses to user requests),and/or hardware (e.g., gate level logic, field-programmable gate array,purpose-built silicon, etc.).

In some cases, flicker values may be kept as low as possible orotherwise improved using techniques disclosed herein. In some cases, thedisclosed techniques can be used, for example, to optimize or otherwiseimprove the efficiency of a given solid-state light source 110 of agiven LCom-enabled luminaire 100, for example, in low or otherwisefavorable ambient lighting conditions. In some cases, use of thedisclosed techniques may permit the use of less complex driverelectronics (e.g., driver 120) for solid-state light sources 110, forexample, as compared to current light-based communication approachesinvolving high-speed light modulation. In some cases, use of thedisclosed techniques may allow for use of low-bandwidth receivers, suchas typical smartphone cameras, in computing device 200 for purposes ofLCom.

It should be noted, however, that the present disclosure is not solimited only to dynamic light modulation, as in some other embodiments,full light modulation without ambient light level feedback may beutilized. As will be appreciated in light of this disclosure,utilization of the disclosed adaptive light modulation scheme, a fulllight modulation scheme, or a high-frequency light modulation scheme maybe based, in part or in whole, on considerations related to efficiency,longevity, light quality (e.g., flicker), cost, and/or hardwareavailability (e.g., inclusion of a photodiode or other suitable lightsensor with the receiver computing device 200).

Techniques for Emitting Position Information from LCom-EnabledLuminaires

FIG. 7A illustrates an example LCom system, including LCom-enabledluminaire 100 and computing device 200, in accordance with an embodimentof the present disclosure. In this example system, LCom-enabledluminaire 100 may be any LCom-enable luminaire as variously describedherein. In addition, computing device 200 may be any computing device,as variously described herein, and computing device 200 may beconfigured to receive LCom signals emitted/transmitted from LCom-enabledluminaire 100. In this example embodiment, luminaire 100 includes atleast one light source configured to emit data 700 via an LCom signal,as variously described herein. Data 700 may include position informationfor the luminaire or its light sources, such as relative and/or absoluteposition information, as will be described in more detail herein. Data700 may also include an environment identifier, as will also bedescribed in more detail herein. Data 700 may also includeidentification (ID) for luminaire 100. In some embodiments, luminaire100 may include on-board memory 130 that stores data 700 and/orluminaire 100 may include one or more communication modules 170 toreceive the position information (e.g., via a wired and/or wirelesscommunication medium). Also, in some embodiments, luminaire 100 may beprogrammable via, for example, a programming interface that at leastallows for the configuration of data 700.

FIG. 7B illustrates an example method for emitting position informationfrom an LCom-enabled luminaire, in accordance with an embodiment of thepresent disclosure. For ease of description, the example LCom systemillustrated in FIG. 7A will be used to describe the method of FIG. 7B.However, any suitable LCom system may be used to implement the method ofFIG. 7B. The method of FIG. 7B includes emitting 701, by at least onesolid-state light source of luminaire 100, a light output. Emission 701may be performed using any suitable techniques as variously describedherein. The method of FIG. 7B continues with modulating 703 the lightoutput to emit an LCom signal, the LCom signal comprising data 700 thatincludes position information indicating the physical location of the atleast one light source and/or luminaire 100. Modulating 703 may beperformed using at least one modulator 174 and any other componentry, aswill be apparent in light of the present disclosure. Data 700 mayinclude relative position information, absolute position information,and/or an environment identifier (ID). In embodiments where theenvironment identifier (ID) is included in data 700, the environment IDmay indicate which map(s) to use for interpretation of the positioninformation, as will be described in more detail herein. In addition,the environment ID may indicate the type of entity where luminaire 100is located, such as a train, aircraft, ship, elevator, etc. Further, theenvironment ID may indicate the specific entity where luminaire 100 islocated, such as a specific retail store building, a specific navalship, a specific elevator within a building, etc.

In some embodiments, data 700 includes relative position information forluminaire 100. In some cases, the relative position information includescoordinates relative to a point of origin or physical location withinthe environment of luminaire 100. In some cases, the relative positioninformation includes the six degrees of freedom offsets relative to apoint of origin or physical location, which can include height offset,offset in the north/south direction, offset in the west/east direction,and/or pitch, roll, and yaw of luminaire 100. In some such cases, thepoint of origin and/or position information for the point of origin maybe provided using data 700, the environment ID, and/or the luminaire ID(e.g., using a lookup table). In some cases, data 700 may includerelative position information for helping to determine the physicallocation of luminaire 100. Emitting relative position information may beparticularly beneficial for moving/mobile luminaires, such as luminairesin ships, trains, aircrafts, and elevators, for example. In the case ofmoving/mobile luminaires, the dynamic position information may beupdated in real time. For example, in the case of a luminaire in anelevator, the floor position of the luminaire may be updated in realtime as it moves between floors, using any suitable technique as will beapparent in light of this disclosure.

In some embodiments, data 700 includes absolute position information forluminaire 100. In some cases, the absolute position information mayinclude the global coordinates of luminaire 100. In some such cases, theglobal coordinates may be obtained via a GPS receiver. In some cases,the absolute position information may include position information forluminaire 100 relative to a point of origin and the absolute position ofthe point of origin. In some such cases, the point of origin and/orposition information for the point of origin may be provided using data700, the environment ID, and/or the luminaire ID (e.g., using a lookuptable). In some cases, data 700 may include absolute positioninformation for helping to determine the physical location of luminaire100. The absolute position information may be static if luminaire 100 islocated within a building, for example, and the absolute positioninformation may be dynamic if luminaire 100 is located within a movingenvironments, such as a ship, train, aircraft, or elevator, for example.In the case of moving/mobile luminaires, the dynamic positioninformation may be updated automatically or in real time. For example,in the case of a luminaire in a ship, the absolute position informationof the luminaire (e.g., the global coordinates) and/or the absoluteposition information for a point of origin or physical location used tocalculate the absolute position of the luminaire may be updated in realtime as the ship moves, using any suitable technique as will be apparentin light of this disclosure.

An example alternative to the techniques for emitting positioninformation from an LCom-enabled luminaire includes receiving aluminaire identifier (ID) via an LCom signal, but no positioninformation, and then determining the position of the luminaire usingthe ID (e.g., via a lookup table). However, such an alternative mayconsume more memory, lead to higher computational overhead, and/orconsume more energy or power. Therefore, the techniques variouslydescribed herein can be used to more effectively and/or efficientlyprovide luminaire position information. In addition, by emittingposition information from the luminaire via an LCom signal, thetechniques may allow for a more open protocol where receivers can decodeand use the position information directly without referring to lookuptables, for example. In addition, the techniques may provide benefitsfor mobile luminaires, such as being able to update dynamic positioninformation in real time at the luminaire without having to update anexternal source, such as a lookup table, for example. Such benefits canalso be realized when luminaires are moved to a different location.Additional benefits of the techniques will be apparent in light of thepresent disclosure.

Techniques for Selective Use of Light-Sensing Devices in LCom

As will be appreciated in light of this disclosure, the cameras andsensors native to existing smartphones and other mobile computingdevices are not originally designed for LCom. As such, there are anumber of non-trivial challenges associated with establishing LCombetween luminaires and receiver devices using such cameras and sensors.In addition, there are non-trivial challenges in using such devices tocalculate positioning, for example, for purposes of indoor positioning.

Thus, and in accordance with some embodiments, techniques are disclosedfor determining how and when to utilize a given light-sensitive device(e.g., a front-facing image capture device 252; a rear-facing imagecapture device 254; an ambient light sensor 265) of a computing device200 for purposes of detecting the pulsing light of LCom signalstransmitted by an LCom-enabled luminaire 100. In accordance with someembodiments, determination of whether to utilize only an image capturedevice 250, only an ambient light sensor 265, or a combination thereofin gathering LCom data may be based, in part or in whole, on factorsincluding time, location, and/or context.

FIG. 8A is a flow diagram illustrating a method of receiving LCom dataoptionally utilizing multiple light-sensing devices of a computingdevice 200, in accordance with an embodiment of the present disclosure.As can be seen, the flow may begin as in block 801 with detecting anLCom signal with a first light-sensing device at a first sampling rate.In some embodiments, the first light-sensing device may be, for example,an image capture device 250 of computing device 200. In some such cases,the first sampling rate may be, for example, in the range of about 24-60frames per second (FPS). In some other embodiments, the firstlight-sensing device may be, for example, an ambient light sensor 265 ofcomputing device 200. In some such cases, the first sampling rate maybe, for example, in the range of about 300 Hz or greater. Other suitablelight-sensing devices and sampling rates will depend on a givenapplication and will be apparent in light of this disclosure.

Thereafter, the flow may continue as in block 803 with decoding firstLCom data from the detected LCom signal, and as in block 805 withanalyzing the first LCom data. In accordance with some embodiments,decoding and/or analyzing of the first LCom data may be performed, inpart or in whole, via one or more processors 220 of computing device200. In some cases, decoding and/or analysis of the first LCom data maybe facilitated via one or more applications 216 of computing device 200.

In some cases, the flow optionally may continue thereafter as in block807 with detecting the LCom signal with a second light-sensing device ata second sampling rate. If the first light-sensing device is an ambientlight sensor 265 of computing device 200, then in some cases the secondlight-sensing device may be, for example, an image capture device 250 ofcomputing device 200. If instead the first light-sensing device is animage capture device 250 of computing device 200, then in some cases thesecond light-sensing device may be, for example, an ambient light sensor265 of computing device 200. As will be appreciated in light of thisdisclosure, the second sampling rate may be any of the example samplingrates discussed above, for instance, with respect to the first samplingrate of the first light-sensing device of computing device 200, inaccordance with some embodiments. In some cases, the second samplingrate may be substantially the same as (e.g., exactly the same as orwithin a given tolerance of) the first sampling rate. In some othercases, the second sampling rate may be different from the first samplingrate.

Thereafter, the flow optionally may continue as in block 809 withdecoding second LCom data from the detected LCom signal, and as in block811 with analyzing the second LCom data. In accordance with someembodiments, decoding and/or analyzing of the second LCom data may beperformed, in part or in whole, via one or more processors 220 ofcomputing device 200. In some cases, decoding and/or analysis of thesecond LCom data may be facilitated via one or more applications 216 ofcomputing device 200.

FIG. 8B is a flow diagram illustrating a method of receiving LCom dataoptionally utilizing multiple light-sensing devices of a computingdevice 200, in accordance with another embodiment of the presentdisclosure. As can be seen, the flow may begin as in block 821 withdetecting an LCom signal with a first light-sensing device at a firstsampling rate and with a second light-sensing device at a secondsampling rate. As will be appreciated in light of this disclosure, thefirst and second light-sensing device can be any one or more of thosediscussed above, for instance, with respect to FIG. 8A (e.g., an imagecapture device 250; an ambient light sensor 265). As will be furtherappreciated, the first and second sampling rates may be any of theexample sampling rates discussed above, for instance, with respect toFIG. 8A. In some cases, the first and second sampling rates may besubstantially the same (e.g., exactly the same or within a giventolerance). In some other cases, the first and second sampling rates maybe different from one another.

Thereafter, the flow may continue as in block 823 with decoding firstand second LCom data from the detected LCom signal, and as in block 825with analyzing the first and second LCom data. In accordance with someembodiments, decoding and/or analyzing of the first and second LCom datamay be performed, in part or in whole, via one or more processors 220 ofcomputing device 200. In some cases, decoding and/or analysis of thefirst and second LCom data may be facilitated via one or moreapplications 216 of computing device 200.

In some cases, detection of an LCom signal with a second light-sensingdevice may be performed, for example, at some time subsequent todetection of that LCom signal with a first light-sensing device (e.g.,as in FIG. 8A); that is, detection via the first and secondlight-sensing devices may be performed consecutively, in accordance withsome embodiments. In some such cases, only one of the first and secondlight-sensing devices may be performing detection of the LCom signal ata given time. In some other such cases, one of the first and secondlight-sensing devices may be performing detection of the LCom signal,and then the other of the first and second light-sensing devices maybegin performing simultaneous detection of the LCom signal at a latertime. In some other cases, detection of an LCom signal with a secondlight-sensing device may be performed, for example, at the same time asdetection of that LCom signal with a first light-sensing device (e.g.,as in FIG. 8B); that is, detection via the first and secondlight-sensing devices may be performed simultaneously, in accordancewith some embodiments. In some such cases, both of the first and secondlight-sensing devices may begin performing detection of the LCom signalat the same time. In accordance with some embodiments, detection via thefirst and/or second light-sensing devices may be performed continuously,periodically, or otherwise as desired for a given target application orend-use.

In some cases, the first and second LCom data may be different, in partor in whole, from one another. In some other cases, the first and secondLCom data may be duplicative, in part or in whole, of one another. Insome instances, one or both of the first and second LCom data may below-speed LCom data (e.g., as can be detected by an image capture device250). In some instances, one or both of the first and second LCom datamay be high-speed LCom data (e.g., as can be detected by an ambientlight sensor 265). In accordance with some embodiments, either or bothof the first and second light-sensing devices may be enabled in responseto at least one of detection, decoding, and/or analysis of a given LComsignal. In accordance with some embodiments, either or both of the firstand second light-sensing devices may be disabled in response to at leastone of detection, decoding, and/or analysis of a given LCom signal.

Numerous variations on the methodologies of FIGS. 8A and 8B will beapparent in light of this disclosure. As will be appreciated, and inaccordance with some embodiments, each of the functional boxes (e.g.,801; 803; 805; 807; 809; 811) shown in FIG. 8A and each of thefunctional boxes (e.g., 821; 823; 825) shown in FIG. 8B can beimplemented, for example, as a module or sub-module that, when executedby one or more processors 220 or otherwise operated, causes theassociated functionality as described herein to be carried out. Themodules/sub-modules may be implemented, for instance, in software (e.g.,executable instructions stored on one or more computer readable media),firmware (e.g., embedded routines of a microcontroller or other devicewhich may have I/O capacity for soliciting input from a user andproviding responses to user requests), and/or hardware (e.g., gate levellogic, field-programmable gate array, purpose-built silicon, etc.).

As previously noted, either or both of the first and secondlight-sensing devices of the flows of FIG. 8A-8B can be, in accordancewith some embodiments, an image capture device 250 (e.g., front-facingimage capture device 252; rear-facing image capture device 254) ofcomputing device 200. Depending on its particular configuration, a givenimage capture device 250 may be capable of detecting millions of pixels(e.g., 1,000×1,000 pixels or more, as desired for a given targetapplication or end-use), whereas ambient light sensor 265 may beconsidered, in a general sense, a single-pixel image capture devicecapable of detecting only the average value of light coming through itsoptics. Thus, as will be appreciated in light of this disclosure, thereis a wide range of contexts in which it may be desirable, for example,to utilize a front-facing image capture device 252 exclusive of (orotherwise in preference over) ambient light sensor 265 in detecting LComsignals.

For instance, as will be appreciated in light of this disclosure, incommencing LCom-based indoor navigation, it may be desirable to ensurecalculation of an accurate and reliable point of reference for a givenindoor navigation map. As will be further appreciated, front-facingimage capture device 252 generally may be better suited to that end thanambient light sensor 265. Thus, in accordance with some embodiments,front-facing image capture device 252 may be utilized exclusive of (orotherwise in preference over) ambient light sensor 265, for example, tocollect LCom information during an initial positioning determination forpurposes of calculating a given point of reference in LCom-based indoornavigation. Though front-facing image capture device 252 may have alower sampling rate than ambient light sensor 265, and thus decoding ofa received LCom signal may take longer, a user generally may be moreforgiving of time delays at the beginning of the indoor navigationprocess, understanding that it may take a little time to initiate.

As will be appreciated in light of this disclosure, during an LCom-basedindoor navigation session, computing device 200 may detect unreliableLCom data (e.g., via ambient light sensor 265) resulting, for instance,from crosstalk between neighboring LCom-enabled luminaires 100 or poorrate line alignment between computing device 200 and a giventransmitting LCom-enabled luminaire 100. In accordance with someembodiments, if an unreliable LCom signal is detected, then front-facingimage capture device 252 may be utilized exclusive of (or otherwise inpreference over) ambient light sensor 265, for example: (1) to resolveany LCom crosstalk by determining which LCom-enabled luminaire 100 istransmitting which LCom signal; and/or (2) to assist a user in aligningcomputing device 200 with respect to a given LCom-enabled luminaire 100(as discussed herein). As will be further appreciated, it may bedesirable to remedy these conditions, for example, for purposes ofreliably and accurately calculating absolute position from availableLCom signals, and in some cases, front-facing image capture device 252generally may be better suited to that end than ambient light sensor265. After resolving any crosstalk, front-facing image capture device252 may continue to be utilized, for example, in detecting any availableLCom signal(s), in accordance with some embodiments.

In accordance with some embodiments, front-facing image capture device252 may be utilized exclusive of (or otherwise in preference over)ambient light sensor 265, for example, in gathering reliable andaccurate LCom data from a given LCom-enabled luminaire 100 at a periodicinterval, a user-configurable interval, or otherwise as frequently asdesired for a given target application or end-use. In some cases, thismay help to reduce taxing of system resources (e.g., hardware, software,and/or firmware) of computing device 200 or otherwise schedule periodsof higher resource usage at more convenient times for computing device200.

Also, as previously noted, either of the first or second light-sensingdevices of the flows of FIGS. 8A-8B can be, in accordance with someembodiments, an ambient light sensor 265 of computing device 200.Depending on its particular configuration, ambient light sensor 265 maybe capable of being sampled at a higher sampling rate (e.g., about 300Hz or more, as desired for a given target application or end-use) thanfront-facing image capture device 252, which may have a relativelylimited frame rate of only 24-60 FPS. Also, depending on its particularconfiguration, reading/sampling of ambient light sensor 265 may consumefewer system resources (e.g., hardware, software, and/or firmwareresources) of a host computing device 200 than reading/sampling of afront-facing image capture device 252 hosted thereby. Furthermore,depending on its particular configuration, ambient light sensor 265 andfront-facing image capture device 252 may be distinct from one anotherand thus utilization of ambient light sensor 265 in detecting light maynot restrict the ability to utilize front-facing image capture device252 in capturing image data (e.g., taking pictures/video; scanning acode; etc.). Thus, as will be appreciated in light of this disclosure,there is a wide range of contexts in which it may be desirable, forexample, to utilize ambient light sensor 265 exclusive of (or otherwisein preference over) front-facing image capture device 252 in detectingLCom signals.

In accordance with some embodiments, ambient light sensor 265 may beutilized exclusive of (or otherwise in preference over) front-facingimage capture device 252, for example, to constantly monitor thesurrounding environment for LCom signals from any available LCom-enabledluminaires 100. This may be desirable, for example, in some cases inwhich computing device 200 is constantly or otherwise frequently movingaround. Also, as will be appreciated in light of this disclosure,ambient light sensor 265 may be relatively easier to poll thanfront-facing image capture device 252. In an example case, ambient lightsensor 265 may detect a change (e.g., a relative change or a coarseupdate) in a light pattern sensed from the surrounding environment,signifying that computing device 200 has moved to a location near adifferent transmitting LCom-enabled luminaire 100. In some such cases,front-facing image capture device 252 thereafter may be utilized, forexample, to establish a reliable signal with the nearby LCom-enabledluminaire 100, in accordance with some embodiments.

In accordance with some embodiments, ambient light sensor 265 may beutilized exclusive of (or otherwise in preference over) front-facingimage capture device 252, for example, in correcting errors in LCom datastreams received by front-facing image capture device 252 duringinterruptions caused, for instance, by abrupt movements of computingdevice 200. To that end, ambient light sensor 265 may be utilized, forexample, to detect light pulses from a given transmitting LCom-enabledluminaire 100 to fill in for missing LCom data, in accordance with someembodiments. For instance, consider the example case in which computingdevice 200 is tilted such that a given LCom-enabled luminaire 100 thatwas initially within the FOV of front-facing image capture device 252 isnow no longer within the FOV, temporarily or otherwise. In someinstances, ambient light sensor 265 still may be at least somewhataligned with that LCom-enabled luminaire 100, and thus it can be used indetecting LCom signals from the LCom-enabled luminaire 100, for example,until front-facing image capture device 252 is once again sufficientlyaligned therewith, in accordance with some embodiments. Also, in casesin which computing device 200 includes a gyroscopic sensor 267, tiltangle and other information may be available for that computing device200 to make intelligent decisions with regard to how to fill in themissing LCom data, in accordance with some embodiments.

In accordance with some embodiments, ambient light sensor 265 may beutilized exclusive of (or otherwise in preference over) front-facingimage capture device 252, for example, to sample at higher speeds ineffort to detect the presence of high-speed LCom data signals. Forinstance, consider the example case in which an LCom-enabled luminaire100 initially transmits LCom data (e.g., such as its position and/orother indoor navigation information) with a comparatively slower pulsespeed that can be detected by front-facing image capture device 252 ofcomputing device 200, and then transmits additional LCom data (e.g.,such as an in-store promotional special/sale and/or other indoornavigation information) with a comparatively higher pulse speed that canbe detected by ambient light sensor 265 of computing device 200, inaccordance with some embodiments. To that end, depending on itsparticular configuration, ambient light sensor 265 may be generallybetter suited than front-facing image capture device 252 at detectinghigh-speed light pulses. To illustrate, consider FIGS. 8C and 8D, whichare two example image frames of magnified pixel output of a front-facingimage capture device 252 receiving LCom signal input from two separatetransmitting LCom-enabled luminaires 100, in accordance with anembodiment of the present disclosure. As demonstrated here, as betweenthe two different image frames (one frame at time t₁; the other frame 66ms later at time t₂), the pulsing light of the LCom signal transmittedby the two source LCom-enabled luminaires 100 may not be effectivelydetected across the frames of pixel output of front-facing image capturedevice 252 having a frame rate, for example, of 30 FPS or 60 FPS.Contrariwise, consider FIG. 8E, which is a graph of power ratio as afunction of frequency illustrating an example output signal of anambient light sensor 265 receiving LCom signal input from two separatetransmitting LCom-enabled luminaires 100, in accordance with anembodiment of the present disclosure. As demonstrated here, the pulsinglight of the LCom signal transmitted by the source LCom-enabledluminaires 100 is clearly detected by ambient light sensor 265, asevidenced by the graphed output (twenty plotted data points over 66 ms)of ambient light sensor 265 having a sampling rate, for example, of 300Hz. In some cases, use of ambient light sensor 265 in detectinghigh-speed LCom signals may help to prevent or otherwise reduce any needfor making hardware and/or driver changes to a computing device 200,such as a smartphone or other mobile computing device.

As will be appreciated in light of this disclosure, the front-facingimage capture device 252 of computing device 200 may be utilized in manydifferent ways by computing device 200 (e.g., by any of a wide range ofdifferent applications 216 thereof). As such, there may be occasionswhere a user wishes to utilize some other function of computing device200, temporarily or otherwise, while LCom is active. For instance, in anexample case, a user may wish to utilize computing device 200 to scan abar code or a quick response (QR) code of a product. In some such cases,to that end, computing device 200 may disable front-facing image capturedevice 252 and instead enable rear-facing image capture device 254. Inanother example case, a user may wish to utilize computing device 200 tomake a telephone call or engage in some other communication session. Insome such cases, to that end, computing device 200 may disable one orboth of front-facing image capture device 252 and rear-facing imagecapture device 254. Thus, in accordance with some embodiments, ambientlight sensor 265 may be utilized exclusive of (or otherwise inpreference over) front-facing image capture device 252, for example, todetect incoming LCom signals, keeping LCom active in such scenarios.

As will be further appreciated in light of this disclosure, there isalso a wide range of contexts in which it may be desirable, for example,to utilize front-facing image capture device 252 and ambient lightsensor 265 in conjunction with one another in detecting LCom signals.For instance, in accordance with some embodiments, ambient light sensor265 may be utilized to detect transmitted LCom light pulses within itsFOV, and front-facing image capture device 252 may be utilized todetermine the location of the LCom-enabled luminaire 100 that is thesource of the most dominant LCom signal. This information may becombined and decoded, in accordance with some embodiments, to determinewhere the transmitting LCom-enabled luminaire is located and what LComdata is being transmitted thereby.

Depending on its particular configuration, ambient light sensor 265 maybe capable of sampling LCom light pulses faster than front-facing imagecapture device 252, and front-facing image capture device 252 may becapable of more readily detecting the source LCom-enabled luminaire 100.Thus, in accordance with some embodiments, ambient light sensor 265 maybe utilized to detect high-frequency LCom data signals, whilefront-facing image capture device 252 may be utilized to resolve thesource LCom-enabled luminaire 100 of that high-speed LCom data, andcomputing device 200 can utilize both pieces of information in decodinghigh-frequency LCom signals. For instance, consider the example case inwhich front-facing image capture device 252 has two neighboringLCom-enabled luminaires 100 within its FOV—one to the left of computingdevice 200 and the other to the right of computing device 200. Based onLCom data gathered by front-facing image capture device 252, computingdevice 200 may provide instructions to tilt it towards a certain one ofthe adjacent LCom-enabled luminaires 100, and ambient light sensor 265then may be utilized to sense the light pulses at a comparatively higherspeed than could be provided by front-facing image capture device 252,in accordance with some embodiments. Computing device 200 then mayidentify which LCom-enabled luminaire 100 is communicating and thereforedetermine how to utilize the LCom light pulses detected by ambient lightsensor 265, in accordance with an embodiment. Likewise, front-facingimage capture device 252 can be utilized, in accordance with someembodiments, to determine when to read ambient light sensor 265, such aswhen that ambient light sensor 265 is much closer to one LCom-enabledluminaire 100 than another LCom-enabled luminaire 100 so as to minimizeor otherwise reduce crosstalk.

In some cases, when front-facing image capture device 252 is aimed, forexample, at an overhead transmitting LCom-enabled luminaire 100, thecontrast between the LCom-enabled luminaire 100 and its backdrop may beso stark that the auto-exposure setting of front-facing image capturedevice 252 may be quickly thrown off, introducing a varying noise floor.Thus, in accordance with some embodiments, the ambient light leveldetected by ambient light sensor 265 may be utilized to control theexposure setting of front-facing image capture device 252, therebyhelping to minimize or otherwise reduce variations in the noise floor.It should be noted, however, that the present disclosure is not solimited, as in some embodiments, front-facing image capture device 252may be configured to calibrate itself, in part or in whole, based onmeasured pixels.

In an example scenario, a user may enter an LCom-enabled location (e.g.,such as a store or other site having LCom-enabled luminaires 100)looking for an item of interest. Once inside the LCom-enabled location,the user may initiate an indoor navigation application 216 on computingdevice 200 to guide him/her to the item of interest. When the indoornavigation application 216 opens, the front-facing image capture device252 of computing device 200 may search within its FOV for an LCom signalfrom an overhead or otherwise nearby transmitting LCom-enabled luminaire100. Upon detection of an LCom signal, the exact location in space ofthe source LCom-enabled luminaire 100 may be received by computingdevice 200 via that LCom signal. Computing device 200 then may calculateits present position, for example, using: (1) the location informationreceived via the LCom signal transmitted by the source LCom-enabledluminaire 100; and/or (2) information provided by one or more sensors260 hosted by computing device 200 (e.g., such as tilt informationprovided by a gyroscopic sensor 267 of computing device 200). Once theinitial navigation location is calculated, computing device 200 mayswitch to monitoring LCom signals with ambient light sensor 265 togather additional information, such as promotional specials, calibrationdata, and/or any other data. Meanwhile, front-facing image capturedevice 252 may continue to monitor nearby LCom-enabled luminaires 100 toaid in decoding received LCom signals and/or detecting a change in thesituation. At this point, computing device 200 may have successfullycollected all the information from a given nearby LCom-luminaire 100,and a navigation application 216 of computing device 200 may be ready toguide the user onward. As the user moves within the LCom-enabledlocation, ambient light sensor 265 may continuously monitor LCom signalsand look for changes in transmission patterns, which would indicate thatcomputing device 200 has moved beneath or otherwise near a differenttransmitting LCom-enabled luminaire 100. When a change is detected,front-facing image capture device 252 may come back online, establish anew orientation of the LCom-enabled luminaires 100 within its FOV, andlet ambient light sensor 265 know when to proceed with detectingavailable LCom signals. Meanwhile, front-facing image capture device 252may reliably detect any slower, basic LCom data available. Thisswitching between front-facing image capture device 252 and ambientlight sensor 265 may continue throughout the user's indoor navigationexperience to achieve reliable, high-speed LCom data interpretation fromthe on-site LCom-enabled luminaires 100, in accordance with someembodiments.

In another example scenario, front-facing image capture device 252 andambient light sensor 265 may be used simultaneously (e.g., rather thanswitching between the two). Here, front-facing image capture device 252may determine which transmitting LCom-enabled luminaire 100 is thesource of the light output, and ambient light sensor 265 may detect anyavailable high-frequency LCom signals. This may allow for a coarseorientation to be computed by computing device 200 to orient the userrelative to a given transmitting LCom-enabled luminaire 100. Forinstance, front-facing image capture device 252 may estimate that atransmitting LCom-enabled luminaire 100 is some distance ahead ofcomputing device 200, while ambient light sensor 265 may detect an LComsignal that the source LCom-enabled luminaire 100 is at a certain set ofcoordinates in space. Using such data, the location of computing device200 (and thus the user, if present) can be determined, in accordancewith some embodiments.

It should be noted, however, that any of the example contexts,scenarios, and uses discussed herein with respect to utilizing afront-facing image capture device 252 only or otherwise in preferenceover an ambient light sensor 265 are not so limited, as in accordancewith some other embodiments, a combination of front-facing image capturedevice 252 and ambient light sensor 265 can be utilized in any givensuch context, scenario, or use, as desired for a given targetapplication or end-use. Similarly, any of the example contexts,scenarios, and uses discussed herein with respect to utilizing anambient light sensor 265 only or otherwise in preference over afront-facing image capture device 252 are not so limited, as inaccordance with some other embodiments, a combination of ambient lightsensor 265 and front-facing image capture device 252 can be utilized inany given such context, scenario, or use, as desired for a given targetapplication or end-use. Likewise, any of the example contexts,scenarios, and uses discussed herein with respect to utilizing acombination of ambient light sensor 265 and front-facing image capturedevice 252 are not so limited, as in accordance with some otherembodiments, front-facing image capture device 252 or ambient lightsensor 265 can be utilized exclusively or otherwise in preference in anygiven such context, scenario, or use, as desired for a given targetapplication or end-use. Numerous configurations and applications of thetechniques disclosed herein will be apparent in light of thisdisclosure.

In some cases, use of techniques disclosed herein may realize benefitsderived, for example, from efficacious use of various advantagesprovided by a front-facing image capture device 252 and/or variousadvantages provided by an ambient light sensor 265 of a host computingdevice 200. In some cases, use of the disclosed techniques may providefor reliable LCom linking and/or LCom data transfer rates between agiven transmitting LCom-enabled luminaire 100 and a given receivingcomputing device 200. Some embodiments may provide for reliable andaccurate LCom data transfer that is useful, for instance, to indoornavigation and/or other navigation and positioning contexts. Someembodiments may utilize componentry that is native to or otherwisealready present on a computing device 200, such as a smartphone or othermobile computing device.

Techniques for Raster Line Alignment in LCom

Existing approaches for using a camera to decode pulsed light inlight-based communication involve making assumptions about geometry andrely on having the receiving camera positioned directly under ordirectly in front of the pulsing light source. Furthermore, with theseexisting approaches, pulsing speeds are severely limited so that lighttransitions can be detected by a large number of raster lines of thereceiving camera to keep the signal-to-noise ratio (SNR) sufficientlylow. This is because the receiving camera does not know the pixelspacing between light sources and therefore the delay between lightsignals, and therefore worst-case scenarios are assumed.

As discussed herein, a given LCom-enabled luminaire 100 can beconfigured to transmit information about its absolute position, and thatinformation can be utilized by a computing device 200 to determine itslocation based on its proximity to the transmitting LCom-enabledluminaire 100, in accordance with some embodiments. Thus, theinformation transmitted by a given LCom-enabled luminaire 100 can beutilized, in accordance with some embodiments, to provide for indoornavigation which exhibits improved accuracy, for example, as compared toexisting GPS-based and WPS-based navigation techniques. However, as willbe appreciated in light of this disclosure, successful indoor navigationusing LCom may depend, at least in part, on proper alignment of theimage sensor of a given image capture device 250 of computing device 200relative to a given transmitting LCom-enabled luminaire 100 involved inthe indoor navigation process.

Thus, and in accordance with some embodiments, techniques are disclosedfor providing proper raster line alignment of a given image capturedevice 250 (e.g., front-facing image capture device 252; rear-facingimage capture device 254) relative to a transmitting LCom-enabledluminaire 100 to establish reliable LCom there between. As discussedherein, in some cases, proper alignment can be provided automatically(e.g., by computing device 200 and/or other suitable controller). Insome cases, proper alignment can be provided by the user. In someinstances in which a user is to be involved in the alignment process,computing device 200 may be configured to instruct or otherwise guidethe user in the process of properly aligning it relative to a giventransmitting LCom-enabled luminaire 100. In some cases, the raster linealignment techniques disclosed herein can be utilized, for example, torealize improvements in successful LCom signal transmission, baud rate,SNR, overall system performance, and/or error rate. In accordance withsome embodiments, the raster line alignment techniques disclosed hereincan be utilized, for example, in scenarios in which a computing device200 detects that a signal carrier (e.g., an LCom signal) is present, butthat device 200 receives no or only partial LCom data and thus cannotdecode the LCom data of the detected signal. In some cases, thedisclosed raster line alignment techniques can be utilized, for example,in scenarios in which LCom is established between a computing device 200and an LCom-enabled luminaire 100 but there is insufficient LCom datathroughput (e.g., for internet browsing, video streaming, or otherapplication involving high LCom data throughput).

FIG. 9A is a flow diagram illustrating a method of providing instructionto achieve proper alignment of an image capture device 250 relative to atransmitting LCom-enabled luminaire 100, in accordance with anembodiment of the present disclosure. As can be seen, the flow may beginas in block 901 with surveying the surrounding environment for anLCom-enabled luminaire 100 transmitting an LCom signal. To that end, anyof front-facing image capture device 252, rear-facing image capturedevice 254, and/or ambient light sensor 265 may be utilized. In somecases, a given image capture device 250 may perform a rolling shutterimage capture to facilitate detection of LCom light pulses and thusdetermine which LCom-enabled luminaires 100 (if any) within its FOV areactively transmitting LCom signals. In performing a rolling shutterimage capture, the image sensor of image capture device 250 may scansequential raster lines (e.g., sequential rows of pixels) with pausesbetween the raster lines so that the previous raster line is collectedright before the timing of the next image frame (e.g., the completecollection of rows and columns of pixels). Thus, consider the examplecase in which there are 100 raster lines in the image frame. If imagecapture device 250 is operating at a frame rate of 30 FPS, then eachimage frame is 1/30 seconds (about 0.033 s) long, and the time delaybetween gathering raster lines is about 0.033 s/100 raster lines (about0.00033 s/raster line). By using a rolling shutter image capture, anylight transients may be collected because, at any specified time, somepixel of image capture device 250 is collecting light. As will beappreciated in light of this disclosure, the timing of the event may bedictated by which raster line detects the light transition(s). Thus,assuming the example conditions noted above, if the light output of agiven LCom-enabled luminaire 100 pulses at 300 Hz, then every 10 rasterlines of the image capture device 250 of computing device 200 woulddetect a transition.

Thereafter, the flow may continue as in block 903. If no LCom signal isdetected by computing device 200, then the flow may return to block 901,and surveying of the surrounding environment may be performed again, ifdesired. If instead an LCom signal is detected by computing device 200,then the flow may continue as in block 905 with determining thealignment of the image capture device 250 relative to the one or moretransmitting LCom-enabled luminaires 100 within the FOV (hereinafterreferred to as the one or more LCom-enabled luminaires 100 of interest).

In making a raster line alignment determination, several parameters maybe calculated or otherwise determined by computing device 200 (e.g., bythe one or more processors 220 thereof). First, the position of a givenLCom-enabled luminaire 100 of interest within the FOV of the imagecapture device 250 of computing device 200 may be determined. To thisend, it may be desirable to ensure that the LCom-enabled luminaire 100is fully within the FOV of the image capture device 250 (e.g.,front-facing image capture device 252; rear-facing image capture device254) so as to fully qualify that LCom-enabled luminaire 100 as a validsource of LCom data. In some cases, this may help to minimize orotherwise reduce susceptibility of computing device 200 to detectingfalse sources of LCom signals, such as reflection of a distantLCom-enabled luminaire 100, which might otherwise yield a falsedetermination of location. In some instances, the contrast in brightnessof a given LCom-enabled luminaire 100 of interest as compared to itssurroundings (e.g., ceiling, wall, mounting surface, etc.) mayfacilitate identification of a clear outline of the LCom-enabledluminaire 100 for purposes of determining its location.

Second, the geometry of the one or more LCom-enabled luminaires 100 ofinterest may be determined. To that end, the longest dimension (L) of agiven LCom-enabled luminaire 100 may be determined. In some cases, thelongest dimension (L) may be readily identified, for example, byobserving the shape of the LCom-enabled luminaire 100 of interest. Todetect the geometry of the one or more LCom-enabled luminaires 100 ofinterest, a given image capture device 250 may perform a normal shutterimage capture (e.g., switching from a rolling shutter image capturemode, as utilized in surveying, discussed above), as this will leave theimage sensor of the image capture device 250 active for a period of timethat is much longer than the pulsing of the light (thus temporarilyignoring the pulsing of the light), thereby creating a clear image ofthe orientation of the one or more LCom-enabled luminaires 100 ofinterest.

Third, if a paired arrangement of LCom-enabled luminaires 100 ofinterest is observed, then the orientation of its constituentLCom-enabled luminaires 100 may be determined. To that end, the twoLCom-enable luminaires 100 of the paired arrangement may pulse slowly atthe start of their LCom sequence so that even a misaligned raster fieldof a given image capture device 250 can detect the orientation of thetwo LCom-enable luminaires 100. In some cases, the orientationinformation determined here may be supplemented with additionalinformation about the paired arrangement of LCom-enabled luminaires 100,such as the fact that the two constituent LCom-enabled luminaires 100are arranged, for example, in parallel or in serial according to theirlonger dimension (L).

Fourth, the raster direction of the image capture device 250 may bedetermined. The raster direction may be a constant hardware parameterinherently designated by the particular configuration of the imagecapture device 250 (e.g., front-facing image capture device 252;rear-facing image capture device 254) of computing device 200. In someother cases, however, the raster direction may be adjustable, forexample, in terms of how the image capture device 250 addresses thepixels in frame and/or how the image capture device 250 rotates itselfwithin or otherwise with respect to the host computing device 200.

After determination of the position, geometry, and orientation of theone or more LCom-enabled luminaires 100 of interest, the rasterdirection of image capture device 250 (e.g., front-facing image capturedevice 252; rear-facing image capture device 254) may be comparedagainst that information to accurately determine the alignment of theimage capture device 250 relative to the one or more LCom-enabledluminaires 100 of interest. FIG. 9B illustrates an example scenario ofimproper alignment between the raster direction of a front-facing imagecapture device 252 of a computing device 200 and a dual arrangement ofpaired transmitting LCom-enabled luminaires 100, in accordance with anembodiment of the present disclosure. Here, the two LCom-enabledluminaires 100 of interest are arranged substantially parallel to oneanother, and the raster line of front-facing image capture device 252detects only one constituent LCom-enabled luminaire 100 at a time,resulting in faulty transition data. Contrariwise, FIG. 9C illustratesan example scenario of proper alignment between the raster direction offront-facing image capture device 252 of a computing device 200 and adual arrangement of paired transmitting LCom-enabled luminaires 100, inaccordance with an embodiment of the present disclosure. Here, theraster line of front-facing image capture device 252 detects bothconstituent LCom-enabled luminaires 100 at the same time, resulting invalid transition data.

In accordance with some embodiments, determination of the alignmentbetween an image capture device 250 and a given transmittingLCom-enabled luminaire 100 may involve measuring the quality of thedetected LCom signal. To that end, it may be desirable in some cases toensure that the captured image of the one or more transmittingLCom-enabled luminaires 100 encompasses the entire LCom data packetwithin a single CMOS image frame of image capture device 250. In someinstances, the optimality (or other quality metric) of a detected LComsignal may depend on a number of factors, such as, for example: (1) thequantity of raster lines or total number of coherent pixels thatcorrespond to a unique transmitting LCom-enabled luminaire 100; (2) thefixed scan time per raster line of image capture device 250; (3) thefixed packet length of LCom data transmitted by a transmittingLCom-enabled luminaire 100; and/or (4) the orientation of a given imagecapture device 250 of computing device 200 (e.g., which may depend, inpart or in whole, on the position of the host user or other hostplatform). As will be further appreciated, in some cases the scan timeand packet length may be generally fixed parameters, whereas thequantity of raster lines or total number of coherent pixels may be ameasured quantity, and the orientation of image capture device 250 maybe user-configurable or otherwise variable, as desired for a giventarget application or end-use.

Thereafter, the flow may continue as in block 907 with determiningwhether there is misalignment (e.g., as compared to an optimal or othertarget alignment) between the image capture device 250 and a giventransmitting LCom-enabled luminaire 100. In accordance with someembodiments, such a determination may involve computation of an optimalor other desired position and/or orientation of that image capturedevice 250. To that end, the longest dimension (L) of the transmittingLCom-enabled luminaire 100 geometry may be substantially aligned (e.g.,precisely aligned or otherwise within a given tolerance) with thedirection of the raster scan of the image capture device 250 ofcomputing device 200. In some cases, the raster line may besubstantially perpendicular (e.g., exactly perpendicular or otherwisewithin a given tolerance) to the longest dimension (L) of thetransmitting LCom-enabled luminaire 100. In accordance with someembodiments, the quantity of coherent pixels per transmittingLCom-enabled luminaire 100 may be counted continuously. Thus, ifcomputing device 200 is moved around and this count increases, then thatmay signify that the LCom signal strength has improved. If instead thecount decreases, then that may signify that the LCom signal strength hasweakened, and it may be desirable to return the image capture device 250to its previous position and/or orientation in order to improve the LComsignal strength (e.g., by maximizing the quantity of coherent pixelscounted by computing device 200). As will be appreciated in light ofthis disclosure, for a given known LCom-enabled luminaire 100 geometry,if an obstruction is blocking the image sensor of image capture device250, then it may be desirable to move that image capture device 250 (orotherwise move computing device 200) so that the entire transmittingLCom-enabled luminaire 100 is detected (e.g., in the direction of theraster scan). As will be further appreciated, in some cases it may bedesirable to optimize positioning, for example, in scenarios where datastreaming (e.g., high LCom data throughput) is desired.

If the image capture device 250 is not misaligned with respect to theone or more LCom-enabled luminaires 100 of interest, then the flow mayreturn to block 901, and surveying of the surrounding environment may beperformed again, if desired. If instead the image capture device 250 isdetermined to be misaligned relative to the one or more LCom-enabledluminaires 100 of interest, then the flow may continue as in block 909with outputting instruction on how to reorient the image capture device250 to provide proper alignment with the one or more LCom-enabledluminaires 100 of interest. In some cases, the instruction may be by wayof one or more control signals (e.g., from a processor 220; from acontroller 270) that cause computing device 200 to automaticallyreorient (e.g., move, rotate, or otherwise reposition) itself and/or itsimage capture device(s) 250 so that: (1) the one or more LCom-enabledluminaires 100 of interest are centered or otherwise properly within theFOV of the image capture device 250; and/or (2) the raster lines of theimage capture device 250 are properly aligned with the one or moreLCom-enabled luminaires 100 of interest. In some other cases, theinstruction may be by way of one or more control signals (e.g., from aprocessor 220; from a controller 270) that cause computing device 200 toautomatically adjust the raster setup of the image sensor of a givenimage capture device 250, for instance, in terms of how it addresses thepixels in frame and/or how the image capture device 250 rotates itselfwithin or otherwise with respect to the host computing device 200.

In some still other cases, the instruction may be by way of an on-screeninstruction or other guidance cue from computing device 200 intended toguide the user on how to manually reorient (e.g., move, rotate, orotherwise reposition) it and/or its image capture device(s) 250 so that:(1) the one or more LCom-enabled luminaires 100 of interest are centeredor otherwise properly within the FOV of image capture device 250; and/or(2) the raster lines of the image capture device 250 are properlyaligned with the one or more LCom-enabled luminaires 100 of interest. Tothat end, computing device 200 may provide the user with visual feedbackvia display 230 (e.g., via a GUI presented thereat). For example,consider FIG. 9D, which illustrates an example scenario in whichcomputing device 200 is configured to output instruction by way ofvisual feedback to a user, in accordance with an embodiment of thepresent disclosure. As can be seen here, in this example case, the GUIpresented at display 230 of computing device 200 shows that thefront-facing image capture device 252 of computing device 200 is notproperly aligned with respect to an LCom-enabled luminaire 100 ofinterest. The GUI presented at display 230 also provides on-screenfeedback that signifies that the user should move forward with thecomputing device 200 toward the LCom-enabled luminaire 100 of interestto provide for proper alignment between front-facing image capturedevice 252 and that LCom-enabled luminaire 100. In another example case,if computing device 200 determines that the one or more LCom-enabledluminaires 100 of interest are oriented parallel to the raster lines ofa given image capture device 250, then it may instruct/guide the user torotate the image capture device 250 by 90° to provide proper alignment(e.g., before continuing with indoor navigation). In some embodiments,computing device 200 may be configured to provide a visual aid (e.g.,aligning crosshairs; matching rectangles; aligning a target image orsilhouette; directional arrows, for instance, in case computing device200 is in motion, such as when the user is walking) which assists theuser in aligning the LCom-enabled luminaire 100 with the direction ofthe raster scan of a given image capture device 250 of computing device200. It should be noted, however, that the present disclosure is not solimited only to instruction by way of visual feedback, as in accordancewith some other embodiments, audio (e.g., sound emitted via audio outputdevice 280), haptic (e.g., vibration emitted by an actuator, such as avibratory motor), and/or any other suitable type of feedback may beprovided to a user, as desired for a given target application orend-use. In an example case, aural feedback may be provided as a beepingsound that increases in frequency as a target orientation is approached,followed by a constant tone when the target alignment is achieved. Inanother example case, a voice may provide verbal commands that can befollowed by a user in reorienting to achieve a target alignment. In someembodiments, audio feedback may be provided to a user to suggest a bestor otherwise desirable position for optimal LCom signal strength based,for example, on at least one of position and/or orientation. Othersuitable feedback types will depend on a given application and will beapparent in light of this disclosure.

In the case of a single LCom-enabled luminaire 100 of interest pulsingits light output, it may be desirable to ensure that the raster lines ofa given image capture device 250 (e.g., front-facing image capturedevice 252; rear-facing image capture device 254) are substantiallyparallel (e.g., precisely parallel or otherwise within a giventolerance) to the longest dimension (L) of that LCom-enabled luminaire100. In some instances, this type of alignment may help to isolatetransient effects and/or improve SNR by allowing the active raster lineto detect more of the pulsing light at one time, as opposed to merelydetecting a small cross-section. Otherwise, if the raster line of theimage capture device 250 is misaligned relative to the transmittingLCom-enabled luminaire 100, then the portion of the light detected bythe raster line may be very small and thus have a much higher noiselevel, negatively impacting the SNR. To this end, computing device 200may automatically reorient image capture device 250 and/or provideon-screen instruction or other guidance to a user on how to reorient itso that the raster lines properly align with the single LCom-enabledluminaire 100, for example, in order to capture the longest dimension(L) of the LCom-enabled luminaire 100 for optimal (or other desired)SNR, in accordance with some embodiments.

In the case of a dual arrangement of LCom-enabled luminaires 100 ofinterest communicating as a pair by pulsing their light output, forinstance, in opposite polarities (e.g., one LCom-enabled luminaire 100is actively emitting and the other LCom-enabled luminaire 100 shuts offto keep the ambient light level constant and be less noticeable tonearby observers during the LCom sequence), it may be desirable toensure that both of the constituent LCom-enabled luminaires 100 aredetected by the same raster line of a given image capture device 250(e.g., front-facing image capture device 252; rear-facing image capturedevice 254) of computing device 200 (e.g., as in FIG. 9B). Otherwise, araster line may detect a transition of one constituent LCom-enabledluminaire 100, but not detect the transition in the other constituentLCom-enabled luminaire 100 until some unknown time later (e.g., as inFIG. 9A). This may result in LCom break down because it is nearlyimpossible to analyze transitions given that the delay time in detectionbetween the two constituent LCom-enabled luminaires 100 of the dualpaired arrangement depends on parameters unknown to computing device200. To this end, computing device 200 may automatically reorient imagecapture device 250 and/or provide on-screen instruction or otherguidance to a user on how to reorient it so that a given raster lineproperly aligns with the two constituent LCom-enabled luminaires 100, inaccordance with some embodiments.

It should be noted that the alignment techniques disclosed herein neednot be utilized continuously, and instead may be reserved, for example,for use in certain particular conditions and contexts that may ariseduring a given indoor navigation session. For instance, the properalignment techniques disclosed herein may be utilized, in accordancewith some embodiments, when reading an initial LCom-enabled luminaire100 to initiate an indoor navigation session. In accordance with someembodiments, the proper alignment techniques disclosed herein may beutilized when an LCom signal needs refinement, such as in cases in whichmultiple LCom-enabled luminaires 100 are sufficiently close to a targetwhere refinement of position is desired. If for some reason it is notparticularly convenient to reorient computing device 200 with respect toa given LCom-enabled luminaire 100 of interest, then even justdetermining that the raster lines of a given image capture device 250are misaligned with respect thereto can be used, for example, to modifythe LCom (e.g., to perhaps a more stable but not fully accurate state).

In accordance with some other embodiments, the pulsing frequency of thelight pulses emitted by a given LCom-enabled luminaire 100 may bereduced, for example, to a point where those pulses are not smaller interms of the pixels of image capture device 250 than the separationbetween the paired LCom-enabled luminaires 100. For instance, considerthe example case in which an image capture device 250 is configured todetect 1,000 pixels×1,000 pixels. If two paired LCom-enabled luminaires100 occupy half of the screen, then the separation between them is 500pixels. Applying the double frequency principle, it follows thattransitions may not happen any less than 1,000 pixels. As such,transmission is limited to 15 Hz for an image capture device 250 havinga frame rate, for example, of 30 FPS. Under such conditions,approximately 2 bytes of LCom data may be transmitted per second. Thus,a transmission, for example, of longitude, latitude, altitude, ID, andperhaps some other piece of information would take several seconds,during which time the user would stand idly near the paired LCom-enabledluminaires 100 collecting the LCom data. However, this may not guaranteean alignment of the raster line of image capture device 250 relative toa given LCom-enabled luminaire 100. If instead the raster line of imagecapture device 250 were properly aligned with an LCom-enabled luminaire100, then transmission speeds could be greatly increased (e.g., about50× faster assuming 10 pixels to declare a good transition), and an LComtransmission of 10 bytes of LCom data would take only a fraction of asecond, in accordance with an example embodiment.

Some embodiments may avoid or otherwise reduce limitations on pulsingspeeds that may be imposed by typical SNR considerations in light-basedcommunication. As a result, in some cases, the faster pulsing speeds mayreduce the total time window needed for transmission of a given LComsignal, thus reducing the amount of time that a user must wait near atransmitting LCom-enabled luminaire 100 to ensure successful receipt ofany LCom data transmitted thereby. Some embodiments may realizeimprovements in reliable detection and decoding of LCom signalstransmitted by single LCom-enabled luminaires 100 and/or by pairedarrangements LCom-enabled luminaires 100. In some cases, use of thedisclosed techniques may reduce susceptibility of a computing device 200to detecting false sources of LCom signals, such as reflections, andthus improve the ability to provide accurate and reliable positioninginformation (e.g., for indoor navigation). In some cases, techniquesdisclosed herein can be used, for example, to compensate for unknowngeometries which otherwise would be required for addressing misalignmentbetween the raster line of an image capture device 250 and anLCom-enabled luminaire 100 of interest.

Techniques for Determining an LCom Receiver Position

FIG. 10A illustrates an example LCom system, including LCom-enabledluminaire 100 and LCom receiver 200, in accordance with an embodiment ofthe present disclosure. In the example system, the LCom receiver 200 isa smart phone; however, LCom receiver 200 may be any computing device asvariously described herein. In this embodiment, the receiver 200includes an image capture device 252, which in this example system is acamera (and more specifically a front-facing camera). Note that thecamera/image capture device may be integrated with the receiver, such asis the case with receiver 200, or the camera/image capture device may beexternal to the receiver and communicatively coupled (e.g., in a wiredor wireless manner). In addition, luminaire 100 may be any LCom-enabledluminaire as variously described herein.

FIG. 10B illustrates an example method of determining an LCom receiverposition, in accordance with an embodiment of the present disclosure.For ease of description, the example LCom system illustrated in FIG. 10Awill be used to describe the method of FIG. 10B. However, any suitableLCom system may be used to implement the methodology, as will beapparent in light of this disclosure. The example method includesgenerating 1021, by a camera 252 having a field of view (FOV), an imagewithin the FOV. In some embodiments, the method may instead or alsoinclude receiving the image from the camera 252. The method alsoincludes identifying 1023 an LCom-enabled luminaire within the image1010. As shown in FIG. 10A, image 1010 is displayed on a display ofreceiver 200 and image 1010 includes luminaire 100 having a pixel length1012. In some embodiments, luminaire 100 is identified 1023 using anLCom signal transmitted from luminaire 100. Additional or alternativedata may be transmitted by luminaire 100 via an LCom signal, as will bedescribed herein; however, if receiver 200 has at least anidentification (ID) of luminaire 100, then additional information can beobtained in another suitable manner using that ID, such as via a lookuptable, for example.

The method of FIG. 10B continues with calculating 1025 the distance 1014from receiver 200 to luminaire 100. Calculation 1025 may use geometry ofluminaire 100, the size and/or position of luminaire 100 in image 1010,and the zoom factor of image 1010. The geometry of the luminaire mayinclude, for example, the length 1002 of luminaire 100, the width ofluminaire 100, the orientation of lights or panels within luminaire 100,and/or any other information about the geometry of luminaire 100. Thegeometry of luminaire 100 may be obtained via an LCom signal transmittedfrom luminaire 100 or in another suitable manner, such as via a lookuptable using the ID of luminaire 100, for example. The size and/orposition of luminaire 100 in image 1010 may be determined based on thepixel information representing luminaire 100, for example, or any othersuitable manner. For example, the pixel length 1012 of luminaire 100 canbe seen in image 1010, and pixel length 1012 can be compared to theactual luminaire length 1002 when calculating 1025 distance 1014. Thezoom factor of image 1010 may be determined based on the specificationsof the camera and/or the image generation method, such as the propertiesof the lens, for example, or any other suitable factors. Calculation1025 may be performed using any other suitable technique, as will beapparent in light of this disclosure.

The method of FIG. 10B continues with calculating 1027 the position ofreceiver 200 relative to luminaire 100 using distance 1014 and theorientation of receiver 200 relative to luminaire 100. The position ofreceiver 200 relative to luminaire 100 may be expressed as a vectorposition, for example. The orientation of receiver 200 relative toluminaire 100 may be determined using fiducial 1006 or some otherrecognizable aspect of luminaire 100 as an orientation cue. For example,the location of fiducial 1006 can be seen in image 1010, which can beused to help orient receiver 200 relative to luminaire 100. Fiducialsmay include special markings on the luminaire, a non-symmetric luminairedesign aspect, a unique geometry of the luminaire, or any other suitableaspect of the luminaire recognizable by the receiver. In someembodiments, the fiducial need not be directly on or a part of theluminaire (e.g., the fiducial may be adjacent to the luminaire). In anycase, the fiducial may merely be associated with luminaire 100 and maybe detectable within image 1010 generated by camera 252. In someembodiments, the fiducial may be a virtual fiducial created by the lightoutput by luminaire 100 (e.g., as described herein with reference to amultiple panel luminaire). The orientation of receiver 200 relative toluminaire 100 may also be determined using the yaw, pitch, and roll 1004of luminaire 100 and/or the yaw, pitch, and roll 1008 of receiver 200.The yaw, pitch, and roll 1004 of luminaire 100 may be obtained via anLCom signal transmitted from luminaire 100 or in another suitablemanner, such as via a lookup table using the ID of luminaire 100, forexample. The yaw, pitch, and roll 1008 of receiver 200 (e.g., relativeto the ground or floor) may be determined using a gyroscope, such as aninternal gyroscope, for example. In some embodiments, yaw, pitch, androll 1004 and/or 1008 may be used to calculate 1025 distance 1014. Theorientation of receiver 200 relative to luminaire 100 may also bedetermined using the heading of receiver 200. The heading (e.g., compassor absolute heading) of receiver 200 may be determined using ageomagnetic sensor, such as an internal geomagnetic sensor, for example.The orientation may also be determined using any other suitabletechnique, as will be apparent in light of this disclosure. Once thedistance 1014 and orientation of receiver 200 relative to luminaire 100are determined, the position of receiver 200 relative to luminaire 100can be calculated using any suitable technique.

The method of FIG. 10B optionally continues with calculating 1029 theabsolute position of receiver 200. Calculation 1029 may use the absoluteposition of luminaire 100 and the position of receiver 200 relative toluminaire 100 (determined in calculation 1027). The absolute position ofluminaire 100 may be obtained via an LCom signal transmitted fromluminaire 100 or in another suitable manner, such as via a lookup tableusing the ID of luminaire 100, for example. The techniques for emittingposition information from an LCom-enabled luminaire as variouslydescribed herein may also be used to determine the absolute position ofluminaire 100.

In an example case of the LCom system illustrated in FIG. 10A, luminaire100 has a length of four feet by one foot. If it is determined that thesize of luminaire in image 1010 takes up forty pixels by ten pixels,distance 1014 can then be calculated using the zoom factor of image1010. Once distance 1014 is calculated 1025, the position of receiver200 can be calculated 1027 to be anywhere on the surface of a spherehaving a radius about equal to distance 1014, based on calculation 1025.Fiducial 1006 can then be used to orient receiver 200 relative toluminaire 100 and determine the vector position of receiver 200 relativeto luminaire 100. The orientation determination may then be corrected bythe pitch, roll, and yaw 1004 of luminaire 100 and/or by the pitch,roll, and yaw 1008 of receiver 200. The orientation determination may befurther corrected using the heading of receiver 200. Optionally, theabsolute position of receiver 200 can then be calculated 1029 using theabsolute position of luminaire 100 and the position of receiver 200relative to luminaire 100. Note that in some embodiments, receiverpositioning may be performed using the absolute position and geometryinformation of a single luminaire in conjunction with the image of theluminaire (which can be used to resolve the observed geometry of theluminaire). In some such embodiments, the positioning technique mayinclude computing the relative position of the smart device with respectto the luminaire, based on the geometry and geometrical referencepoint(s) of the luminaire. Further, in some such embodiments, inertialsensors (e.g., accelerometers and/or gyroscopic sensors) need not bepresent in, or utilized by, the receiver.

The techniques for determining an LCom receiver position shown in FIGS.10A and 10B and described herein are provided in the context of having asingle LCom-enabled luminaire within the FOV of the receiver for ease ofdescription. However, the techniques can be used to determine an LComreceiver position when any number of LCom-enabled luminaires are withinthe FOV of the receiver. In some instances, when there are multipleLCom-enabled luminaires within the FOV of the receiver, the position ofthe receiver may be determined with greater accuracy/precision, becausethe receiver will have more than one point of reference for calculatingits relative position, for example. Similarly, the accuracy/precision ofthe relative position of the receiver may also be improved when anLCom-enabled luminaire within the FOV of the receiver is transmittingmore than one LCom signal, such as in the case of a multiple panelLCom-enabled luminaire, as variously described herein. Also note thatalthough the techniques for determining an LCom receiver position areprimarily discussed herein with reference to determining the distance,orientation, position, etc. of the receiver itself, in some embodiments,the distance, orientation, position, etc. of the receiver camera mayalso or alternatively be determined.

An example alternative to the techniques for determining an LComreceiver position described herein includes assuming that the LComreceiver is directly under a luminaire from which it is receiving LComsignals. For small, low hanging luminaires, where the distance from theluminaire to the receiver is a low amount (e.g., a meter or less), theresulting accuracy may be satisfactory. However, in some cases,luminaires may be mounted on high ceilings, such as in a large retailestablishment. In some such cases, the position of the LCom receiverposition may be off by a significant amount, such as greater than 1meter from directly under the luminaire, or some other amount dependingon the target application. Therefore, the techniques variously describedherein can be used to increase the accuracy of the determined LComreceiver position compared to, for example, assuming that the LComreceiver is directly under a luminaire from which it is receiving LComsignals. Additional benefits of the techniques as variously describedcan include the ability to lead a customer to a specific product on ashelf, increased accuracy compared to other positioning systems (e.g.,GPS, WPS, etc.), providing a secure positioning system that can be setup to operate independently from other communication networks (e.g., awide area network (WAN), such as the Internet), and other benefits aswill be apparent in light of the present disclosure.

Augmenting LCom Receiver Positioning

FIG. 11A illustrates an example LCom system, including LCom-enabledluminaire 100 and LCom receiver 200, in accordance with an embodiment ofthe present disclosure. In this example system, receiver 200 includesambient light sensor 265, image capture device(s) 250, accelerometer(s)269, gyroscopic sensor 267, geomagnetic sensor 263, GPS receiver, 1112,and Wi-Fi module 1122 all configured to provide input to processor(s)220. Although receiver 200 need not have all of the componentry shown inFIG. 11A, and receiver 200 may have additional or alternativecomponentry as variously described herein, the specific configurationshown will be used herein for ease of description. As can also be seenin this example embodiment, ambient light sensor(s) 265 and imagecapture device(s) 250 are configured to receive LCom signals from one ormore LCom-enabled luminaires 100, GPS receiver 1112 is configured toreceive GPS signals 1110 (e.g., from a satellite), and Wi-Fi module 1122is configured to receive/transmit Wi-Fi signals 1120 (e.g., from a Wi-Firouter). Accordingly, receiver 200 may be configured to determineposition information using a light based positioning system (e.g., usingLCom signals received from LCom-enabled luminaire 100), GPS, or WPS. Inthis example embodiment, receiver 200 and LCom-enabled luminaire are inbuilding 1100 represented by the dotted line box. However, the dottedline box may also represent a vehicle, such as a bus, plane, ship, ortrain, for example. In addition, Wi-Fi signal 1120 is beingtransmitted/received from within building 1100, while GPS signal 1110 isbeing transmitted from outside of building 1100. The exampleconfiguration and layout in FIG. 11A is provided for illustrativepurposes and is not intended to limit the present disclosure.

In some embodiments, receiver 200 may be configured to augmentpositioning techniques using an inertial navigation system (INS). TheINS may utilize accelerometer(s) 269 and/or gyroscopic sensor 267 tocalculate, via dead reckoning, the position, orientation, and velocityof the receiver. In this manner, receiver 200 can calculate its relativeposition using the INS based on a known starting/reference point orlocation. For example, the following equation may be used for thereceiver INS:{right arrow over (s)}(t)=

+∫_(t) ₀ ^(t)(∫_(t) ₀ ^(t) {right arrow over (a)}(t)dt)dtwhere

is the last valid position of receiver 200 and {right arrow over (a)}(t)the absolute acceleration data computed using accelerometer(s) 269and/or gyroscopic sensor 267. In some embodiments, receiver positioningmay be augmented using the heading of receiver 200, which can beobtained from geomagnetic sensor 263, for example.

FIG. 11B illustrates an example method of augmenting LCom receiverpositioning using an inertial navigation system (INS), in accordancewith an embodiment of the present disclosure. For ease of description,the system of FIG. 11A will be used to describe the methodology. Themethod includes determining 1131 if an LCom signal is detected.Determination 1131 can be performed using any suitable technique, suchas using ambient light sensor(s) 265 and/or image capture device(s) 250.If at 1131, no LCom signal is detected, then the method continues bydetermining 1133 if a GPS and/or WPS signal is detected. In someembodiments, determination 1133 may also include determining if anyother positioning system signal is detected, depending upon theconfiguration of receiver 200. If at 1131, an LCom signal is detected,or at 1133, a GPS/WPS signal is detected, then the method continues byupdating 1135 position information using the detected signal todetermine the location of receiver 200. In some embodiments, the methodprimarily relies on determining receiver 200 positioning informationusing an LCom signal, such that whenever an LCom signal is available, itis used for receiver positioning. This may be the case because the LComsignal(s) may be used for the most accurate positioning techniquecompared to using, for example, GPS and/or WPS signals. In otherembodiments, there may not be a preference. In some embodiments, thelocation of receiver 200 may dictate the positioning system used. Forexample, in some such embodiments, if receiver 200 knows it is outside,then GPS may be used as the default positioning system until receiver200 knows it is inside. Further, in some embodiments, memory and/orpower may be conserved by limiting or prioritizing positioning systemsbased on the environment of receiver 200, the last received positioningsignal of receiver 200, or based on some other factor as will beapparent in light of this disclosure.

Continuing with the method of FIG. 11B, if no LCom signal is detected at1131 and no GPS/WPS signal is detected at 1133, the method continues bystoring 1137 the last known position or location of receiver 200 andusing the INS to determine position information for receiver 200relative to that last known position/location. In some cases, the lastknown position may be the last position updated at 1135. In any case,the last known position may be determined using the last known positionof the receiver based on an LCom signal, a GPS signal, WPS signal,and/or any other suitable technique. In some embodiments, the receiverINS runs parallel to other positioning techniques to continuouslycalculate the relative position of receiver 200. In such cases, box 1137of the method may be continually performed to, for example, increasereceiver positioning accuracy. In other embodiments, the receiver INSmay be activated after losing the communication link to otherpositioning systems (e.g., when no LCom, GPS, or WPS signals aredetected). The method continues from boxes 1135 and 1137 by returning1139 back to box 1131, to continue to determine whether an LCom signal(or GPS/WPS signal) is detected.

A benefit of augmenting position information or receiver positioningusing an LCom receiver INS is that, despite not being able to retrieveposition information from another positioning system, the receiver canstill estimate its approximate location. The techniques may also bebeneficial for estimating vertical positioning and/or heightinformation, such as positioning within an elevator. For example, theINS may be used to estimate elevator floor position relative to thestarting floor (the floor where the elevator was entered). Such anexample may allow the receiver 200 to know when the desired floorposition has been achieved and/or when to exit the elevator. Additionalbenefits will be apparent in light of the present disclosure.

LCom Transmission Protocol

Normally, in light-based communication, the transmitting source consumesthe entire channel bandwidth and thus the receiver device cancommunicate with only one transmitting source at a given time. Formultiple transmitting sources to communicate with the receiver device,there may be need to distinguish and select between the signals of thosetransmitting sources. Thus, in cases involving multiple transmittingsources and/or multiple receiver devices, it may be desirable to includean arbitration mechanism to avoid data packet collisions. Also, if asingle light-based communication channel is broken in such a system,then it may be desirable for the transmitting source to have a redundantchannel to which it can switch in order to successfully completetransmission.

Thus, and in accordance with some embodiments, techniques are disclosedfor allocating LCom data to be transmitted over multiple colors of lightoutput by multiple LCom-enabled luminaires 100 and transmitting thatLCom data in parallel across the multiple colors of light using a timedivision multiple access (TDMA) scheme. In accordance with someembodiments, the disclosed techniques can be used, for example, to allowfor multiple LCom-enabled luminaires 100 to communicate simultaneouslywith a single computing device 200 via LCom. In some cases, thedisclosed techniques can be used, for example, to permit a greaterquantity of LCom-enabled luminaires 100 to be disposed within a givenspace, thereby providing more accurate positioning, for instance, forindoor navigation. In some cases, the disclosed techniques may be used,for example, to provide a computing device 200 with the ability tofilter multiple LCom signals received from different LCom-enabledluminaires 100. In some cases, the disclosed techniques can be used, forexample, to allow multiple LCom channels to be active simultaneously inan LCom system 10.

FIG. 12 illustrates an example arrangement of LCom-enabled luminaires100 configured to communicate via LCom with a computing device 200, inaccordance with an embodiment of the present disclosure. As can be seenhere, there are three LCom-enabled luminaires 100 (labeled L₁, L₂, andL₃), each of which is configured, in accordance with an exampleembodiment, for RGB color-mixing of its light output. Also, as can beseen, the three LCom-enabled luminaires 100 (L₁-L₃) are spatiallyarranged and commissioned such that neighboring LCom-enabled luminaires100 transmit over mutually exclusive (e.g., orthogonal) channels at agiven instant. In other words, no neighboring LCom-enabled luminaires100 communicate over the same LCom channel (e.g., over the same color oflight output) at the same time, in accordance with an embodiment. As canbe seen from the following table, for a given time period ‘T,’ whereT=t₁+t₂+t₃, the three LCom-enabled luminaires 100 (L₁-L₃) transmitunique LCom data to computing device 200 in a simultaneous fashion:

Emissions Color Luminaire Red (R) Green (G) Blue (B) L₁ L₁(R) at t₁L₁(G) at t₂ L₁(B) at t₃ L₂ L₂(R) at t₃ L₂(G) at t₁ L₂(B) at t₂ L₃ L₃(R)at t₂ L₃(G) at t₃ L₃(B) at t₁The entries L₁(R), L₂(G), L₃(B) at t₁ represent a unique LCom channelallocated over spatial and temporal domains. Here, TDMA permits sendingindependent LCom data packets in a sequential manner, in accordance withan embodiment. Once LCom is established between the LCom-enabledluminaires 100 and computing device 200, the LCom data packets may betransmitted by the source LCom-enabled luminaires 100 over various lightchannels (e.g., multiple colors of light emissions) in a round-robinfashion, in accordance with some embodiments.

In some cases, use of the techniques disclosed herein may provide forbackup channels in case of LCom failure, leading to more reliable LComdata transmission. If a specific channel (e.g., a specific color) issubject to more ambient noise than the other channel(s) (e.g., one ormore other colors), then transmission of LCom data in a round-robinmanner may be utilized to ensure that all of the desired LCom data issent via all available channels. If a single LCom channel is broken,then a given LCom-enabled luminaire 100 may switch to a redundant LComchannel (e.g., a different color). In some cases, use of the techniquesdisclosed herein may avoid or otherwise minimize LCom data packetcollisions and/or channel crosstalk between participating LCom-enabledluminaires 100.

It should be noted that, while the disclosed techniques are generallydiscussed in the example context of an RGB color-mixing scheme, thepresent disclosure is not so limited. In a more general sense, and inaccordance with some other embodiments, any color-mixing scheme with anyquantity of constituent colors (e.g., RGBY, RGBW, dual-white, or anyother suitable combination of emissions) may be used, as desired for agiven target application or end-use. Given that the LCom channels arerepresented by the different wavelengths of light, the greater thequantity of colors of light output from participating LCom-enabledluminaires 100, the greater the quantity of available LCom channels, andthus the greater the amount of available bandwidth for LCom, as will beappreciated in light of this disclosure. In some cases in which multiplewhite light-emitting solid-state emitters (e.g., dual-white colorscheme), and thus multiple white light-based LCom channels, areutilized, multiple source LCom-enabled luminaires 100 may be configured,for instance, such that only a given LCom channel communicates with thecomputing device 200 at a given time. As will be further appreciated inlight of this disclosure, in some cases, the light output capabilitiesof a given LCom-enabled luminaire 100 may be selected, in part or inwhole, based on a given tolerable amount of data packet collisioncontrol and/or crosstalk/interference.

Multiple Panel LCom-Enabled Luminaires

FIG. 13A illustrates a store including example multiple panel luminaires100, in accordance with an embodiment of the present disclosure. FIG.13B illustrates a bottom view of an example multiple panel luminaire100, in accordance with an embodiment of the present disclosure. As canbe seen in this example embodiment, luminaire 100 includes eightpanels—1A (1301A), 1B (1301B), 2A (1302A), 2B (1302B), 3A (1303A), 3B(1303B), 4A (1304A), 4B (1304B). The panels will primarily be referredto by their panel number (e.g., 1A, 1B, etc.) for ease of description.The multiple panel luminaires described herein may have any suitableconfiguration. For example, the luminaires may be laid out in arectangular grid having rows and columns, such as shown in FIG. 13B. Inanother example, the luminaires may be laid out in a circulararrangement. Therefore, the multiple panel luminaires are not limited toany particular design or configuration, unless otherwise indicated.Further, the panels of a multiple panel luminaire as variously describedherein may be any discrete grouping of at least one solid-state lightsource. Therefore, the panels may have any shape and size, and are notlimited to any particular design or configuration, unless otherwiseindicated.

In the embodiment of FIG. 13B, each panel includes at least onesolid-state light source and the light sources are configured to outputlight. Luminaire 100 may include any suitable componentry as will beapparent in light of this configuration, including at least onemodulator 174 configured to modulate the light output of the lightsources to allow for emission of LCom signals. In some embodiments, thepanels may be modulated and/or driven independently, such that eachpanel is configured to emit its own LCom signal (and any emitted LComsignal may be attributable to a specific one of the panels). For ease ofdescription, the techniques of controlling a multiple panel luminairemay be described herein assuming that at any given time, each LComsignal may be emitting either a high or a low (or a 1 or a 0) totransmit data, using any suitable technique as will be apparent in lightof this disclosure. In some embodiments, a controller 150 of luminaire100 may be configured to synchronize timing of the LCom signals emittedfrom the panels. In communication terms, the synchronization of thetiming of the LCom signal emitted from the panels may be similar toparallel communication in a computer where each pin of a parallel cablecan transmit information at the same time, but all signals aresynchronized by one common clock.

In embodiments of multiple panel luminaires where the timing of LComsignals emitted from the panels is synchronized, a panel may beconfigured to emit an LCom signal that inverts or duplicates an LComsignal emitted by another panel. For example, if a first panel isconfigured to emit a first LCom signal and a second panel is configuredto emit a second LCom signal, the second LCom signal may be an inverseor a duplicate of the first LCom signal. Using additional panels toinvert or duplicate a signal can help with data integrity. For instance,inverting one panel from another one may allow data to still beeffectively transmitted even if one of the two panels was blocked and/ornoisy. Likewise, panels can be used as checksums or for smart bitcorrection using various suitable logic algorithms. In addition, withthe timing of the LCom signals emitted from the panels synchronized, thetotal light output of the luminaire can be configured to be maintainedat a relatively constant level and/or data emitted from the luminairemay be divided amongst one or more panels, as will be described in moredetail herein.

In the example embodiment shown in FIG. 13B, controller 150 of multiplepanel luminaire 100 is configured to synchronize the timing of the LComsignals emitted from the panels. Further, with the timing of the LComsignals emitted from the panels synchronized, luminaire 100 isconfigured such that the A panels (1A, 2A, 3A, 4A) are each emitting asignal and the corresponding B panels (1B, 2B, 3B, 4B) are emitting acorresponding inverse signal of their counterpart A panel. For example,the LCom signal emitted from panel 1B is the inverse of the LCom signalemitted from panel 1A, the LCom signal emitted from panel 2B is theinverse of the LCom signal emitted from panel 2A, and so on. Therefore,when 1A is emitting a high signal, 1B is emitting a low signal, and viceversa. This is indicated in FIG. 13B where the A panel is eitherbright/white/on (which may represent a high signal) or dark/gray/off(which may represent a low signal), and the corresponding B panel is theother of bright or dark, as can be seen. For example, in the presentstate of multiple panel luminaire 100, panel 1A is dark and Panel 1B isbright. Knowing the inversion scheme for the specific configurationshown in FIG. 13B, it can also be seen that two panel sets have panelsthat are diagonal from each other (1A/1B, 2A/2B) and two panel sets havepanels that adjacent to each other (3A/3B, 4A/4B). This configurationmay be useful for creating a virtual fiducial that can provideorientation information, as will be described in more detail herein.

FIG. 13C illustrates receiver (computing device) 200 viewing multiplepanel luminaire 100 of FIG. 13B from two different orientations, inaccordance with an embodiment of the present disclosure. In this exampleembodiment, receiver 200 is a smart phone that includes a front-facingimage capture device (camera) 252 configured to generate an image 1310,and receiver 200 is viewing luminaire 100 from below the luminaire. Thearrows are provided to indicate receiver headings 1312, 1314 whenobserving the luminaire from below. Luminaire 100 includes the signalinversion pattern described with reference to the example embodiment inFIG. 13B (1A inverts 1B, 2A inverts 2B, etc.). As can be seen from theimages 1310 displayed on the receiver in the two different orientations,when receiver 200 has heading 1312 in a first direction, the image ofthe luminaire is in a first orientation and when receiver 200 hasheading 1314 in a second direction substantially opposite the firstdirection, the image of the luminaire is in a second orientationsubstantially opposite the first orientation. In this manner, multiplepanel luminaire 100 creates a virtual fiducial that can provideorientation information to receiver 200. When receiver 200identifies/observes the entirety of multiple panel luminaire 100,receiver 200 can tell which way the luminaire I oriented based on howthe inverted panels are structured. In some cases, the meaning of theorientation information may be provided via the LCom signal(s) emittedfrom luminaire 100. For example, luminaire 100 may transmit that end ofluminaire 100 where panels 4A and 4B are located faces north or that theend faces an identified point of origin or physical location, such thatreceiver 200 can use the orientation information to, for example,determine its position (e.g., using techniques for determining an LComreceiver position, as variously described herein).

Note that the inversion scheme provided in FIGS. 13B and 13C forcreating a virtual fiducial for orientation purposes is provided forillustrative purposes and is not intended to limit the presentdisclosure. A multiple panel luminaire with as little as two panels maybe used to create a virtual fiducial to provide orientation information.For example, two adjacent panels emitting distinct LCom signals may bespatially resolved (e.g., using the techniques for spatially resolvingreceived LCom signals, as variously described herein), such that thelocation of each LCom signal within the FOV of a receiver can use theposition of the LCom signals as an orientation cue. In another example,a long luminaire that is one panel wide but greater than two panels long(e.g., 100 panels long or any other suitable amount) may still provideposition and/or orientation information, because the panels may beconfigured to emit LCom signals that can be used for receiverpositioning. Also note that in some embodiments of a multiple panelLCom-enabled luminaire, all of the panels need not be capable of orconfigured to emit LCom signals. For example, only one of the panels maybe configured to emit LCom signals, while the other panels areconfigured to output light that is not encoded with data. However, evenin some such embodiments, the multiple panel luminaire may create avirtual fiducial for providing orientation information. Therefore,numerous variations and configurations will be apparent in light of thisdisclosure.

In some embodiments, light quality may be improved using a multiplepanel luminaire. For example, in some such embodiments, the total lightoutput may be maintained a relatively constant level, such that thelight output variance is not perceptible by human vision. Maintainingtotal light output at a relatively constant level may include lightoutput variance of less than 25%, 20%, 15%, 10%, 5%, or 2% lumens, orsome other suitable tolerance as will be apparent in light of thisdisclosure. In some instances, this may be achieved by having the samenumber of panels in a high state as there are in a low state at anygiven time to keep the DC or ambient level relatively constant duringpulsing and LCom emission. In some such instances, this can be donethrough the inversion of signals or through some balancing algorithm.Using the example luminaire of FIG. 13B, which has eight panels witheach panel in either a high or a low state, in the case where there isno panel inversion, 256 different combinations would be possible(calculated by 2⁸). If an inversion rule was implemented such that thenumber of panels in a high state is about the same as the number ofpanels in a low state (no matter which panels), seventy differentcombinations would be possible (calculated using eventprobability—8!/4!/4!). If an inversion rule was implemented such thatfour panels are the inversion of four other panels (such as the casedescribed above), sixteen different combinations would be possible(calculated by 2⁴). Depending on the desired data rate and reliability,the different inversion rules can be applied at different times. Thetable immediately below shows a summary of the different inversionrules:

Inversion Rule Combinations Directionality Same amount of panels “high”as 70 No “low” Four panels invert four others 16 YesAs can be seen in this table, the inversion rule of four panelsinverting four others has fewer combinations and therefore a slower datarate, but the rule provides directionality to the smart phone in termsof providing directionality/creating a virtual fiducial for orientationinformation (as variously described herein). In some embodiments, acombination of the inversion rules may can be applied so that, forexample, one part of the multiple panel luminaire (e.g., panels 1A and1B) always invert each other, but the other panels do not follow such aninversion rule. In some such embodiments, directionality may still beprovided and more combinations may be achieved.

In some embodiments, data transmission speeds and/or reliability can beimproved using multiple panel luminaires. For example, assuming that asingle panel luminaire has two states (e.g., high and low), one data bitcan be transmitted at any given time. With further reference to Table 1,in the case of the inversion rule where four panels invert four others,eight (calculated by sixteen combinations divided by two states) timesthe amount of data compared to a single panel luminaire can betransmitted in a given amount of time (e.g., assuming both luminairesare pulsing with the same frequency). Therefore, data that would takeone second to transmit using the eight panel luminaire applying theinversion rule that four panels invert four others rule would take eightseconds to transmit with a single panel luminaire assuming the samepulsing frequency. Numerous variations and configurations will beapparent in light of this disclosure. Recall that the eight panelluminaire described herein is provided for illustrative purposes and isnot intended to limit the present disclosure. A multiple panel luminairehaving any configuration and any number of panels or groups of lightsources can be used to realize the benefits described herein.

FIG. 13D illustrates an example multiple panel luminaire transmission,in accordance with an embodiment of the present disclosure. As can beseen, the transmission starts with LCom data 1320. The data 1320 isdivided amongst the panels 1330 of the multiple panel luminaire 100 tobe emitted via LCom signals 1325. Luminaire 100 may have any number ‘n’of panels 1330, where each panel includes at least one solid-state lightsource configured to output light. Data 1320 may be divided in anysuitable manner, whether evenly or not, amongst one or more panels 1330of luminaire 100. One or more modulators 174 may be configured tomodulate the light output of the light sources of the panels to allowfor the emission/transmission of LCom signals 1325 which may carry atleast a portion of data 1320. Note, as previously described, in someembodiments, one or more panels of the multiple panel luminaire may notbe configured to emit/transmit an LCom signal. Receiver 200 can receiveLCom signals 1325 in one or more channels 1340 or sections, as variouslydescribed herein (e.g., using techniques for spatially resolvingreceived LCom signals). Receiver 200 can then reconstruct the LCom data1320 using the LCom signals 1325, as shown. This time and/or spacedivision multiplexing can lead to a constant or improved light outputwhile still maintaining a desired communication data rate and/orreliability.

Referring back to FIG. 13A, when a customer comes into the store lookingfor an item, the customer may be able to use an LCom receiver, such astheir smart phone to start an indoor navigation app to guide them to thedesired item. Once the app is activated, the camera on the smart phonemay be configured to identify an LCom signal within its field of viewfrom overhead luminaires 100. If luminaire 100 is identified and an LComsignal is detected, luminaire 100 can provide the exact location of theluminaire in space along with orientation information (e.g., what thepattern of inverted panels mean in terms of heading) to position thesmart phone in space. In addition, data emitted from multiple panelluminaire 100 may be broadcasted at a faster rate than compared to, forexample, a single panel luminaire, because the data can be dividedamongst the LCom signals emitted from the multiple panels. Theimprovement in speed depends upon the particular configuration, butimprovements may be at least 2×, 3×, 5×, 8×, or 10× the speed, or someother suitable amount as will be apparent in light of this disclosure.

An example alternative to a multiple panel LCom-enabled luminaire is asingle panel LCom-enabled luminaire. Single panel luminaires may be ableto provide orientation using an associated fiducial (such as a markingsomewhere on the luminaire); however, using a multiple panel luminaireto create a virtual fiducial as variously described herein may bebeneficial for providing orientation information, because it may bebetter detected by an LCom receiver. In addition, data rates and dataintegrity may be diminished through use of a single panel LCom-enabledluminaire compared to use of a multiple panel LCom-enabled luminaire.Another benefit of multiple panel luminaires as variously describedherein may include being able to communicate to a slow speed receivingdevice, such as a smart phone front facing camera, without anyperceptible visual artifacts. Such a benefit may be realized becausewhen light output is modulated at less than 100 Hz, the quantity andquality of illumination can both get negatively affected, includingissues with flicker and non-uniform illumination levels. Therefore,various benefits of multiple panel LCom-enabled luminaires include beingable to provide orientation information as described herein, being ableto maintain a constant light output and improve the quantity/quality ofillumination provided, being able to transmit data at faster and morereliable rates, being able to establish a communication link with anLCom receiver in a faster and more reliable manner, and other benefitsas will be apparent in light of the present disclosure.

Techniques for Spatially Resolving Received LCom Signals

FIG. 14A illustrates an example field of view 1400 of an image capturedevice 250 and a corresponding image 1402, in accordance with anembodiment of the present disclosure. In this example embodiment, theFOV 1400 and corresponding image 1402 are provided to describetechniques for spatially resolving received LCom signals. As can beseen, the FOV 1400 observed by image capture device 250 (referred to asa camera herein for ease of reference) includes three luminaires. Forease of description, it is assumed that each luminaire seen in FOV 1400is transmitting an LCom signal.

FIG. 14B illustrates an example method of spatially resolving receivedLCom signals, in accordance with an embodiment of the presentdisclosure. For ease of description, the example FOV 1400 and image 1402in FIG. 14A will be used to describe the methodology. The method of FIG.14B includes receiving 1411, by a computing device 200, a digital imageof at least one sold-state light source transmitting one or more LComsignals. The LCom signal(s) may be received/captured by a camera 250 ofthe device 200. The method also includes segmenting 1413 the image intoa plurality of non-overlapping cells 1404, where the LCom signals areeach associated with a unique pixel cluster of the light source capturedin at least one of the cells. Segmenting 1413 can be performed using anysuitable technique(s). The method continues by spatially resolving 1415the one or more LCom signals based on detected unique pixel clusters. Ascan be seen in FIG. 14A, the luminaires in FOV 1400 are shown in thegenerated image 1402, where each luminaire is illustrated as capturedusing corresponding dotted lines. As can also be seen, image 1402 hasbeen segmented into non-overlapping cells 1404 which are rectangular inshape. In some embodiments, each LCom signal can be associated with orinterpreted as a unique pixel cluster comprising at least one of thecells to spatially resolve each LCom signal. Once each LCom signal isdetected as or associated with a unique pixel cluster, that pixelcluster can be used to identify the location/position of the signalwithin the image 1402, along with other benefits that can be derivedfrom spatially resolving each LCom signal, as will be discussed in moredetail herein.

FIG. 14C illustrates an example field of view 1420 of an image capturedevice 250 and a corresponding image 1422, in accordance with anotherembodiment of the present disclosure. The previous discuss withreference to FOV 1400 applies to FOV 1420 and the previous discussionwith reference to image 1402 applies to image 1422. In this exampleembodiment, FOV 1420 includes three luminaires 101, 102, and 103. Forease of description, it is assumed that luminaires 101, 102, and 103 areeach transmitting an LCom signal. Image 1422 is the corresponding imagefrom below the luminaires. As can be seen, image 1422 was segmented intonon-overlapping/unique hexagonal shaped cells 1424, where the receivedLCom signals are each associated with a unique pixel cluster comprisingat least one of the cells 1424. As can also be seen, the observed LComsignals have overlap in the indicated overlap regions 1426, which willbe discussed in more detail herein.

In some embodiments, received signal strength indicator (RSSI)information may be used to help determine the nearest communicatingluminaire. For example, RSSI information for the LCom signals fromluminaires 101, 102, and 103 may be used to assist in spatiallyresolving the LCom signals in image 1422, such as in overlapping regions1426. RSSI information for an LCom signal may be based on the strengthof the received LCom signal, the luminance of the light carrying thesignal, or any other suitable factor as will be apparent in light ofthis disclosure. In some embodiments, the orientation of the LComreceiver may be used to assist in spatially resolving received LComsignals. For example, one or more gyroscopes within the receiver may beconfigured to determine orientation of the receiver (e.g., pitch, roll,and yaw) and the orientation information may be used to assist inspatially resolving the received LCom signals in image 1422, such as inoverlapping regions 1426. In some embodiments, once received LComsignals are spatially resolved, cells associated with LCom signals canbe filtered and focused on to, for example, improve the overall signalto noise ratio. Further, in some such embodiments, each LCom pixelcluster (comprising at least one cell for each LCom signal) can befiltered out and focused on to, for example, improve the signal to noiseratio for that LCom signal. In some embodiments, once received LComsignals are spatially resolved, cells or pixels not associated with anyLCom signal may be filtered out to help improve signal to noise ratiofor the LCom signals. Filtering out cells/pixels that do not carry anyLCom signals can lead to, for example, improved communication speed andenhanced sampling frequency.

In FIGS. 14A and 14C, images 1402 and 1422 were segmented 1413 intorectangular and hexagonal shaped cells, respectively. However,segmenting 1413 may result in any suitable shaped cells, as will beapparent in light of this disclosure. In some embodiments, the cells mayall be similar in size and shape. In some embodiments, the cells may allhave a regular polygon shape. In some embodiments, the cells may berectangular, square, triangular, hexagonal, circular, and/or any othersuitable shape. Whereas using circular shaped cells can leave uncoveredarea, other shapes result in numerous unique and/or non-overlappingcells, such as rectangular, square, triangular, and hexagonal shapedcells. To achieve the best possible granularity with the least number ofunique cells, the image can be segmented 1413 into similar sizedhexagonal cells, such as is the case in FIG. 14C with cells 1422. Thehexagonal cell shape 1422 can be used to maximize image coverage,because for a given distance between the center of a polygon and itsfarthest circumference points, the hexagon has the largest area.Therefore, by using hexagonal cell geometry, the fewest number of cellscan cover an entire space (e.g., with cell sides being held constant).

Note that the techniques and principles described herein for spatiallyresolving received LCom signals may be used for multiple LCom signalsreceived simultaneously from one or more LCom-enabled luminaires.Therefore, the techniques can be used with a single luminaire that istransmitting multiple LCom signals, such as a multiple panel luminaireas variously described herein, or with multiple luminaires that eachtransmit an LCom signal, or with a combination thereof. Also note thatalthough the techniques are described herein in the context of spatiallyresolving more than one LCom signal, the principles can be applied tospatially resolve a single LCom signal within the FOV of an LComreceiver to, for example, increase receiver positioning accuracy. Forexample, in some embodiments, receiver positioning may be performedusing the absolute position of at least two LCom luminaires (which maybe communicated to the receiver via LCom signals) in conjunction withthe image of the signals and information about the receiver tilt (e.g.,yaw, pitch, roll) and orientation (e.g., obtained from an on-boardmagnetometer/geomagnetic sensor). In some such embodiments, thepositioning technique may include spatially resolving the location ofthe at least two luminaires as variously described herein (e.g., bydetermining the origin of the LCom signals of the two luminairesdetected by the receiver) and using the direction/orientation of thereceiver to determine the receiver position/location. Further, in somesuch embodiments, the geometry of the luminaires involved need not beknown.

An example alternative to the techniques for spatially resolvingmultiple LCom signals described herein includes using a photodiodeinstead of a camera or image capture device to establish a line of sightcommunication with an LCom signal source. Such an example alternativedoes not offer the same quality of spatial resolution, including notbeing able to differentiate between multiple LCom signals. Anotherexample alternative includes using a directional photo sensor. However,such an example alternative may include having to direct the directionalphoto sensor toward the LCom signal source(s). Therefore, the techniquesvariously described herein can be used to establish a link with multipleLCom signals within the FOV of a receiver without conflict and/ordetermine the location of those LCom signals. Additional benefits of thetechniques as variously described can include increasing LCom receiverpositioning accuracy/precision, receiving multiple LCom signal sourceseven in areas of signal overlap, improving signal to noise ratio (SNR),enhancing sampling frequency, improving communication speed, being ableto filter out pixels within the FOV that do not include an LCom signal,and other benefits as will be apparent in light of the presentdisclosure.

Numerous variations on the methodologies of FIGS. 5A, 5C, 6C, 7B, 8A,8B, 9A 10B, 11B, and 14B will be apparent in light of this disclosure.As will be appreciated, and in accordance with some embodiments, each ofthe functional boxes shown in these figures can be implemented, forexample, as a module or sub-module that, when executed by one or moreprocessors 140 or otherwise operated, causes the associatedfunctionality as described herein to be carried out. Themodules/sub-modules may be implemented, for instance, in software (e.g.,executable instructions stored on one or more computer readable media),firmware (e.g., embedded routines of a microcontroller or other devicewhich may have I/O capacity for soliciting input from a user andproviding responses to user requests), and/or hardware (e.g., gate levellogic, field-programmable gate array, purpose-built silicon, etc.).

Numerous embodiments will be apparent in light of this disclosure. Oneexample embodiment provides a receiver including: a camera for capturingan image of at least one solid-state light source transmitting one ormore light-based communication (LCom) signals; and a processorconfigured to: segment the image into a plurality of non-overlappingcells, wherein the one or more LCom signals are each associated with aunique pixel cluster of the light source captured in at least one of thecells; and spatially resolve the one or more LCom signals based ondetected unique pixel clusters. In some cases, the one or more LComsignals are visible light. In some instances, the cells are all similarin size and shape. In some such instances, the cells have a regularpolygon shape. In some cases, the cells are hexagonally shaped. In someinstances, the processor is further configured to use receiverorientation information to assist in spatially resolving each LComsignal. In some cases, the processor is further configured to determinereceived signal strength indicator (RSSI) information for each LComsignal to assist in spatially resolving each LCom signal. In some suchcases, the one or more LCom signals are received via visible light andRSSI information is based at least on the luminance of each LCom signal.In some instances, the processor is further configured to filter outcells in the image that are not associated with an LCom signal to assistin spatially resolving each LCom signal. In some cases, a systemincluding the receiver is provided, the system further including atleast one LCom-enabled luminaire, wherein the luminaire is configured totransmit the one or more LCom signals.

Another example embodiment provides a method of light-basedcommunication (LCom), the method including: receiving, by a mobilecomputing device, a digital image of at least one solid-state lightsource transmitting one or more LCom signals; segmenting the image intoa plurality of non-overlapping cells, wherein the one or more LComsignals are each associated with a unique pixel cluster of the lightsource captured in at least one of the cells; and spatially resolvingthe one or more LCom signals based on detected unique pixel clusters. Insome cases, the one or more LCom signals are visible light. In someinstances, the cells are all similar in size and shape. In some cases,the cells are hexagonally shaped. In some instances, the method furtherincludes: using orientation information of the mobile computing deviceto assist in spatially resolving each LCom signal. In some instances,the method further includes: determining received signal strengthindicator (RSSI) information for each LCom signal to assist in spatiallyresolving each LCom signal. In some such instances, the one or more LComsignals are provided via visible light and RSSI information is based atleast on the luminance of each LCom signal. In some cases, the methodfurther includes: filtering out cells in the image that are notassociated with an LCom signal to assist in spatially resolving eachLCom signal.

Another example embodiment provides a non-transitory computer programproduct comprising a plurality of instructions non-transiently encodedthereon that, when executed by one or more processors, cause a processto be carried out. The computer program product may include one or morecomputer-readable mediums, such as, for example, a hard drive, compactdisk, memory stick, server, cache memory, register memory, random-accessmemory (RAM), read-only memory (ROM), flash memory, or any suitablenon-transitory memory that is encoded with instructions that can beexecuted by one or more processors, or a plurality or combination ofsuch memories. The process includes: receiving a digital image of atleast one solid-state light source transmitting one or more light-basedcommunication (LCom) signals; segmenting the image into a plurality ofnon-overlapping cells, wherein the one or more LCom signals are eachassociated with a unique pixel cluster of the light source captured inat least one of the cells; and spatially resolving the one or more LComsignals based on detected unique pixel clusters. In some cases, the oneor more LCom signals are visible light.

The foregoing description of example embodiments has been presented forthe purposes of illustration and description. It is not intended to beexhaustive or to limit the present disclosure to the precise formsdisclosed. Many modifications and variations are possible in light ofthis disclosure. It is intended that the scope of the present disclosurebe limited not by this detailed description, but rather by the claimsappended hereto. Future-filed applications claiming priority to thisapplication may claim the disclosed subject matter in a different mannerand generally may include any set of one or more limitations asvariously disclosed or otherwise demonstrated herein.

What is claimed is:
 1. A receiver comprising: a camera for capturing animage of at least one solid-state light source transmitting one or morelight-based communication (LCom) signals; and a processor configured to:segment the image into a plurality of non-overlapping cells, wherein theone or more LCom signals are each associated with a unique pixel clusterof the light source captured in at least one of the cells; and spatiallyresolve the one or more LCom signals based on detected unique pixelclusters, wherein the processor is further configured to use receiverorientation information to assist in spatially resolving each LComsignal when the unique pixel clusters of the one or more LCom signalsoverlap.
 2. The receiver of claim 1, wherein the one or more LComsignals are visible light.
 3. The receiver of claim 1, wherein the cellsare all similar in size and shape.
 4. The receiver of claim 3, whereinthe cells have a regular polygon shape.
 5. The receiver of claim 1,wherein the cells are hexagonally shaped.
 6. The receiver of claim 1,wherein the processor is further configured to determine received signalstrength indicator (RSSI) information for each LCom signal to assist inspatially resolving each LCom signal.
 7. The receiver of claim 6,wherein the one or more LCom signals are received via visible light andRSSI information is based at least on the luminance of each LCom signal.8. The receiver of claim 1, wherein the processor is further configuredto filter out cells in the image that are not associated with an LComsignal to assist in spatially resolving each LCom signal.
 9. A systemcomprising the receiver of claim 1 and further comprising at least oneLCom-enabled luminaire, wherein the luminaire is configured to transmitthe one or more LCom signals.
 10. A light-based communication (LCom)method comprising: receiving, by a mobile computing device, a digitalimage of at least one solid-state light source transmitting one or moreLCom signals; segmenting the image into a plurality of non-overlappingcells, wherein the one or more LCom signals are each associated with aunique pixel cluster of the light source captured in at least one of thecells; spatially resolving the one or more LCom signals based ondetected unique pixel clusters; and using orientation information of themobile computing device to assist in spatially resolving each LComsignal when the unique pixel clusters of the one or more LCom signalsoverlap.
 11. The method of claim 10, wherein the one or more LComsignals are visible light.
 12. The method of claim 10, wherein the cellsare all similar in size and shape.
 13. The method of claim 10, whereinthe cells are hexagonally shaped.
 14. The method of claim 10, furthercomprising determining received signal strength indicator (RSSI)information for each LCom signal to assist in spatially resolving eachLCom signal.
 15. The method of claim 14, wherein the one or more LComsignals are provided via visible light and RSSI information is based atleast on the luminance of each LCom signal.
 16. The method of claim 10,further comprising filtering out cells in the image that are notassociated with an LCom signal to assist in spatially resolving eachLCom signal.
 17. A non-transitory computer program product encoded withinstructions that, when executed by one or more processors, causes aprocess to be carried out, the process comprising: receiving a digitalimage of at least one solid-state light source transmitting one or morelight-based communication (LCom) signals; segmenting the image into aplurality of non-overlapping cells, wherein the one or more LCom signalsare each associated with a unique pixel cluster of the light sourcecaptured in at least one of the cells; spatially resolving the one ormore LCom signals based on detected unique pixel clusters; and usingorientation information of the mobile computing device to assist inspatially resolving each LCom signal when the unique pixel clusters ofthe one or more LCom signals overlap.
 18. The computer program productof claim 17, wherein the one or more LCom signals are visible light.